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Brian Mann

Professor in the Thomas Lord Department of Mechanical Engineering and Materials Science
Thomas Lord Department of Mechanical Engineering and Materials Science
238 Hudson Hall, Box 90300, Durham, NC 27708-0300
238 Hudson Hall, Box 90300, Durham, NC 27708

Selected Publications


Stability prediction via parameter estimation from milling time series

Journal Article Journal of Sound and Vibration · February 17, 2024 Machine tool vibrations impose severe limitations on industry. Recent progress in solving for the stability behavior of delay differential equations and in modeling milling operations with time delay differential equations has provided the potential to sig ... Full text Cite

Strategies for Improving the Comparison of Frequency Response Functions with Similarity Metrics

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2024 Determining the similarity of an existing structure with a reference structure is an important problem in structural dynamics. For this purpose, many metrics have been developed to quantify the similarity of frequency spectra, such as two transfer function ... Full text Cite

High power electromagnetic vibration harvesting using a magnetic dumbbell structure

Journal Article Journal of Sound and Vibration · March 3, 2023 This paper considers an electromagnetic energy harvester consisting of a tube with two fixed magnets and two coils and containing a floating free-to-move dumbbell structure with two magnets. The dumbbell shape has a number of benefits, including an increas ... Full text Cite

Supervised Learning for Abrupt Change Detection in a Driven Eccentric Wheel

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2023 Event detection is often a predominant challenge in processing non-stationary signals. In engineering mechanics, events may result from non-smoothness in the form of loss of contact, impact, or the onset of sliding-friction. An interesting example of such ... Full text Cite

A Parameter Study of the Matrix Power Control Algorithm

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2023 Environmental testing is very useful for qualifying components for their real-world use. To that end, random vibration testing is performed on component(s) in the laboratory in such a way as to mimic their real-world environment. This is particularly usefu ... Full text Cite

LINEAR ELECTROSTATIC OSCILLATOR WITH VISCOUS DAMPING

Conference Proceedings of the ASME Design Engineering Technical Conference · January 1, 2023 Experimental analysis of a translating spring-mass system with a constant electrostatic force in the presence of viscous damping is presented. The challenge in this effort has been to develop an analytical model for the electrostatic system and experimenta ... Full text Cite

3D Laser-and-Tissue Agnostic Data-Driven Method for Robotic Laser Surgical Planning

Conference IEEE International Conference on Intelligent Robots and Systems · January 1, 2023 In robotic laser surgery, shape prediction of an one-shot ablation crater is an important problem for minimizing errant overcutting of healthy tissue during the course of pathological tissue resection and precise tumor removal. Since it is difficult to phy ... Full text Cite

Improving magnitude and phase comparison metrics for frequency response functions using cross-correlation and log-frequency shifting

Journal Article Journal of Sound and Vibration · October 24, 2022 This paper provides a new method for matching dominant features of Frequency Response Functions (FRFs). In particular, this paper proposes a slicing and shifting method where the key features (in this case, resonant amplitudes) of a baseline FRF are compar ... Full text Cite

A model-free sampling method for basins of attraction using hybrid active learning (HAL)

Journal Article Communications in Nonlinear Science and Numerical Simulation · September 1, 2022 Understanding basins of attraction (BoA) is often a paramount consideration for nonlinear systems. Most existing approaches for determining high-resolution BoA require prior knowledge of the system's underlying math model (e.g., differential equation or po ... Full text Cite

Transfer learning for autonomous chatter detection in machining

Journal Article Journal of Manufacturing Processes · August 1, 2022 Large-amplitude chatter vibrations are one of the most important phenomena in machining processes. It is often detrimental in cutting operations causing a poor surface finish and decreased tool life. Therefore, chatter detection using machine learning has ... Full text Cite

Improving convergence of the Matrix Power Control Algorithm for random vibration testing

Journal Article Mechanical Systems and Signal Processing · January 1, 2022 This paper describes modifications to the Matrix Power Control Algorithm (MPCA) to improve convergence for Random Vibration Control (RVC) testing. In particular, this paper presents Multiple-Input Multiple-Output (MIMO) implementations of MPCA in simulatio ... Full text Cite

The eccentric disk and its eccentric behavior

Journal Article European Journal of Physics · November 1, 2021 Providing example problems that stimulate curiosity and cultivate intuition among students is a prominent responsibility for physics educators. A concept that can be particularly challenging for students to grasp and educators to convey is the relationship ... Full text Cite

Empirical characteristic multiplier estimation: A comparison of methods and improvements

Journal Article Journal of Sound and Vibration · October 27, 2021 Characteristic multipliers (CMs) describe the behavior, such as stability, of a dynamical system near a limit cycle. While existing methods are available to estimate CMs from time series measurements of the system's state, practical challenges such as meas ... Full text Cite

Uncertainty Propagation through An Empirical Model of Cutting Forces in End Milling

Journal Article Journal of Manufacturing Science and Engineering, Transactions of the ASME · July 1, 2021 Empirical mathematical models of cutting forces in machining processes use experimentally determined input parameters to make predictions. A general method for propagation of input parameter uncertainties through such predictive models is developed. Source ... Full text Cite

Primary resonance suppression of a base excited oscillator using a spatially constrained system: Theory and experiment

Journal Article Journal of Sound and Vibration · March 31, 2021 This paper studies the dynamic behaviors of a magnetically coupled oscillator with two-degrees-of-freedom. For the certain parameter combinations, the target component (TC), which is excited by a base movement, enters the saturated steady-state responses. ... Full text Cite

Constrained attractor selection using deep reinforcement learning

Journal Article JVC/Journal of Vibration and Control · March 1, 2021 This study describes an approach for attractor selection (or multistability control) in nonlinear dynamical systems with constrained actuation. Attractor selection is obtained using two different deep reinforcement learning methods: (1) the cross-entropy m ... Full text Cite

Modal analysis of the box assembly with removable component in two configurations

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2021 To ensure accurate predictions of behavior and life-cycle of components in their real-use environment, it is essential to develop accurate simulation and testing procedures that reflect such an environment. For components on machines that experience a sign ... Full text Cite

Electromagnetic vibration energy harvester with ring magnets

Conference "Advances in Acoustics, Noise and Vibration - 2021" Proceedings of the 27th International Congress on Sound and Vibration, ICSV 2021 · January 1, 2021 This work investigates a one-dimensional electromagnetic vibration energy harvester (EMVEH) that uses magnetic interactions to convert ambient vibration into electrical energy. The prototype consists of four coaxial ring permanent magnets enclosed in a tub ... Cite

Improving empirical characteristic multiplier estimation through a change of basis

Journal Article Journal of Sound and Vibration · December 8, 2020 This paper applies empirical Floquet theory to extract characteristic multipliers from time series data and builds upon prior works by significantly reducing the influence of experimental noise. Characteristic multipliers (CMs), which are the eigenvalues o ... Full text Cite

Analytical Force and Flux for a 1-D Electromagnetic Vibration Energy Harvester

Journal Article IEEE Transactions on Magnetics · November 1, 2020 A vibration energy harvester (VEH) converts the kinetic energy of a moving source into electrical energy. In this article, we consider a 1-D electromagnetic vibration energy harvester (1-D EMVEH) that consists of three coaxial cylindrical permanent magnets ... Full text Cite

Stability prediction via parameter estimation from milling time series

Journal Article Journal of Sound and Vibration · February 17, 2024 Machine tool vibrations impose severe limitations on industry. Recent progress in solving for the stability behavior of delay differential equations and in modeling milling operations with time delay differential equations has provided the potential to sig ... Full text Cite

Strategies for Improving the Comparison of Frequency Response Functions with Similarity Metrics

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2024 Determining the similarity of an existing structure with a reference structure is an important problem in structural dynamics. For this purpose, many metrics have been developed to quantify the similarity of frequency spectra, such as two transfer function ... Full text Cite

High power electromagnetic vibration harvesting using a magnetic dumbbell structure

Journal Article Journal of Sound and Vibration · March 3, 2023 This paper considers an electromagnetic energy harvester consisting of a tube with two fixed magnets and two coils and containing a floating free-to-move dumbbell structure with two magnets. The dumbbell shape has a number of benefits, including an increas ... Full text Cite

Supervised Learning for Abrupt Change Detection in a Driven Eccentric Wheel

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2023 Event detection is often a predominant challenge in processing non-stationary signals. In engineering mechanics, events may result from non-smoothness in the form of loss of contact, impact, or the onset of sliding-friction. An interesting example of such ... Full text Cite

A Parameter Study of the Matrix Power Control Algorithm

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2023 Environmental testing is very useful for qualifying components for their real-world use. To that end, random vibration testing is performed on component(s) in the laboratory in such a way as to mimic their real-world environment. This is particularly usefu ... Full text Cite

LINEAR ELECTROSTATIC OSCILLATOR WITH VISCOUS DAMPING

Conference Proceedings of the ASME Design Engineering Technical Conference · January 1, 2023 Experimental analysis of a translating spring-mass system with a constant electrostatic force in the presence of viscous damping is presented. The challenge in this effort has been to develop an analytical model for the electrostatic system and experimenta ... Full text Cite

3D Laser-and-Tissue Agnostic Data-Driven Method for Robotic Laser Surgical Planning

Conference IEEE International Conference on Intelligent Robots and Systems · January 1, 2023 In robotic laser surgery, shape prediction of an one-shot ablation crater is an important problem for minimizing errant overcutting of healthy tissue during the course of pathological tissue resection and precise tumor removal. Since it is difficult to phy ... Full text Cite

Improving magnitude and phase comparison metrics for frequency response functions using cross-correlation and log-frequency shifting

Journal Article Journal of Sound and Vibration · October 24, 2022 This paper provides a new method for matching dominant features of Frequency Response Functions (FRFs). In particular, this paper proposes a slicing and shifting method where the key features (in this case, resonant amplitudes) of a baseline FRF are compar ... Full text Cite

A model-free sampling method for basins of attraction using hybrid active learning (HAL)

Journal Article Communications in Nonlinear Science and Numerical Simulation · September 1, 2022 Understanding basins of attraction (BoA) is often a paramount consideration for nonlinear systems. Most existing approaches for determining high-resolution BoA require prior knowledge of the system's underlying math model (e.g., differential equation or po ... Full text Cite

Transfer learning for autonomous chatter detection in machining

Journal Article Journal of Manufacturing Processes · August 1, 2022 Large-amplitude chatter vibrations are one of the most important phenomena in machining processes. It is often detrimental in cutting operations causing a poor surface finish and decreased tool life. Therefore, chatter detection using machine learning has ... Full text Cite

Improving convergence of the Matrix Power Control Algorithm for random vibration testing

Journal Article Mechanical Systems and Signal Processing · January 1, 2022 This paper describes modifications to the Matrix Power Control Algorithm (MPCA) to improve convergence for Random Vibration Control (RVC) testing. In particular, this paper presents Multiple-Input Multiple-Output (MIMO) implementations of MPCA in simulatio ... Full text Cite

The eccentric disk and its eccentric behavior

Journal Article European Journal of Physics · November 1, 2021 Providing example problems that stimulate curiosity and cultivate intuition among students is a prominent responsibility for physics educators. A concept that can be particularly challenging for students to grasp and educators to convey is the relationship ... Full text Cite

Empirical characteristic multiplier estimation: A comparison of methods and improvements

Journal Article Journal of Sound and Vibration · October 27, 2021 Characteristic multipliers (CMs) describe the behavior, such as stability, of a dynamical system near a limit cycle. While existing methods are available to estimate CMs from time series measurements of the system's state, practical challenges such as meas ... Full text Cite

Uncertainty Propagation through An Empirical Model of Cutting Forces in End Milling

Journal Article Journal of Manufacturing Science and Engineering, Transactions of the ASME · July 1, 2021 Empirical mathematical models of cutting forces in machining processes use experimentally determined input parameters to make predictions. A general method for propagation of input parameter uncertainties through such predictive models is developed. Source ... Full text Cite

Primary resonance suppression of a base excited oscillator using a spatially constrained system: Theory and experiment

Journal Article Journal of Sound and Vibration · March 31, 2021 This paper studies the dynamic behaviors of a magnetically coupled oscillator with two-degrees-of-freedom. For the certain parameter combinations, the target component (TC), which is excited by a base movement, enters the saturated steady-state responses. ... Full text Cite

Constrained attractor selection using deep reinforcement learning

Journal Article JVC/Journal of Vibration and Control · March 1, 2021 This study describes an approach for attractor selection (or multistability control) in nonlinear dynamical systems with constrained actuation. Attractor selection is obtained using two different deep reinforcement learning methods: (1) the cross-entropy m ... Full text Cite

Modal analysis of the box assembly with removable component in two configurations

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2021 To ensure accurate predictions of behavior and life-cycle of components in their real-use environment, it is essential to develop accurate simulation and testing procedures that reflect such an environment. For components on machines that experience a sign ... Full text Cite

Electromagnetic vibration energy harvester with ring magnets

Conference "Advances in Acoustics, Noise and Vibration - 2021" Proceedings of the 27th International Congress on Sound and Vibration, ICSV 2021 · January 1, 2021 This work investigates a one-dimensional electromagnetic vibration energy harvester (EMVEH) that uses magnetic interactions to convert ambient vibration into electrical energy. The prototype consists of four coaxial ring permanent magnets enclosed in a tub ... Cite

Improving empirical characteristic multiplier estimation through a change of basis

Journal Article Journal of Sound and Vibration · December 8, 2020 This paper applies empirical Floquet theory to extract characteristic multipliers from time series data and builds upon prior works by significantly reducing the influence of experimental noise. Characteristic multipliers (CMs), which are the eigenvalues o ... Full text Cite

Analytical Force and Flux for a 1-D Electromagnetic Vibration Energy Harvester

Journal Article IEEE Transactions on Magnetics · November 1, 2020 A vibration energy harvester (VEH) converts the kinetic energy of a moving source into electrical energy. In this article, we consider a 1-D electromagnetic vibration energy harvester (1-D EMVEH) that consists of three coaxial cylindrical permanent magnets ... Full text Cite

Patterned rotary parallel-plate capacitor for frequency up-conversion and RC circuit waveform conditioning

Journal Article Engineering Research Express · June 1, 2020 This paper details a patterned electrostatic rotary capacitive plate design with high energy densities and provides a novel strategy for up-converting low frequency mechanical excitation sources. The rotating plates allow for output waveform signal conditi ... Full text Cite

Potential well hopping and performance of ocean energy harvesters

Journal Article Journal of Sound and Vibration · January 20, 2020 This paper examines a gimballed horizontal pendulum and studies how it can be used to harvest energy from ocean waves. The system's behavior is analyzed under both static and dynamic scenarios. Threshold escape behavior for parametrically excited systems w ... Full text Cite

Vibration testing of laparoscopic surgical instruments under varying grip pressures

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2020 Many devices use vibration to provide sensory cues to a human user. In applications, such as smart phones, the vibratory sensory cue is somewhat simple and needs only to exceed a known threshold to signal the user; however, applications that require an ind ... Full text Cite

Optimizing Logarithmic Decrement Damping Estimation via Uncertainty Analysis

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2020 The logarithmic decrement method is perhaps the most common technique for estimating the damping ratio of linear systems with viscous damping. The approach directly relates the damping ratio to two samples collected from peaks of a recorded free oscillatio ... Full text Cite

Dynamics of a Magnetically Excited Rotational System

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2020 This extended abstract investigates the dynamics of a non-contact linear-to-rotary magnetic transmission system. Equations of motion were derived using a Dipole Model. An equilibria and stability analysis revealed coexisting solutions exist as magnets are ... Full text Cite

An Analysis of the Gimballed Horizontal Pendulum System for Use as a Rotary Vibrational Energy Harvester

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2020 This paper examines a gimballed horizontal pendulum for use as an energy harvester. It can be designed for threshold escape behavior rather than the conventional method of matching frequencies. A nonlinear electromechanical model is developed to study the ... Full text Cite

Reinforcement Learning for Active Damping of Harmonically Excited Pendulum with Highly Nonlinear Actuator

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2020 Active vibration dampers can reduce or eliminate unwanted vibrations, but determining a good control policy can be challenging for highly nonlinear systems. For these types of systems, reinforcement learning is one method to optimize a control policy with ... Full text Cite

Vehicle Escape Dynamics on an Arbitrarily Curved Surface

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2020 This paper derives a planar model for a vehicle on an arbitrarily curved surface. The goal is to investigate different strategies that may be used to free a vehicle from a ditch. More specifically, extricating a modern vehicle typically requires someone to ... Full text Cite

Tuning inertial nonlinearity for passive nonlinear vibration control

Journal Article Nonlinear Dynamics · January 1, 2020 This paper examines the viability of completely passive control approach based on multiple timescale perturbation methods to elicit desired dynamic cancellation or suppression of nonlinear vibration characteristics. Without appeal to feedback, auxiliary os ... Full text Cite

Nonlinear dynamics of a non-contact translational-to-rotational magnetic transmission

Journal Article Journal of Sound and Vibration · October 27, 2019 This paper investigates the dynamics of a non-contact magnetic transmission system that converts translational motion into rotational motion. The system's governing equations, derived under the idealization of a magnetic dipole, were used to obtain analyti ... Full text Cite

Optimizing logarithmic decrement damping estimation through uncertainty propagation

Journal Article Journal of Sound and Vibration · September 29, 2019 This work derives an analytical expression for the optimal number of periods between samples when estimating damping using the logarithmic decrement method. This expression, obtained from an uncertainty analysis of the method's principal equation, is shown ... Full text Cite

Topological optimization of variable area plate capacitors for coupled electromechanical energy harvesters

Journal Article Journal of Intelligent Material Systems and Structures · September 1, 2019 This article examines how topological optimization can be applied to identify nonintuitive capacitor plate patterning that maximizes average power dissipated through an electrical circuit during energy harvesting. Coupled electromechanical equations of mot ... Full text Open Access Cite

Investigating threshold escape behavior for the gimballed horizontal pendulum system

Journal Article Journal of Sound and Vibration · June 23, 2019 This paper examines a gimballed horizontal pendulum for use as an energy harvester. It can be designed for threshold escape behavior rather than the conventional method of matching frequencies. A nonlinear electromechanical model is developed to study the ... Full text Cite

Objective Assessment of the Early Stages of the Learning Curve for the Senhance Surgical Robotic System.

Journal Article J Surg Educ · 2019 OBJECTIVE: The purpose of this research is to study the early stages of the Senhance learning curve to report how force feedback impacts learning rate. This serves as an exploratory investigation into assumptions that fellows and faculty will adjust faster ... Full text Link to item Cite

Predicting oxygen uptake responses during cycling at varied intensities using an artificial neural network

Journal Article Biomedical Human Kinetics · January 1, 2019 Study aim: Oxygen Uptake (VO 2 ) is avaluable metric for the prescription of exercise intensity and the monitoring of training progress. However, VO 2 is difficult to assess in anon-laboratory setting. Recently, an artificial neural network (ANN) was used ... Full text Cite

Intentional nonlinearity in energy harvesting systems

Chapter · January 1, 2019 The success of portable electronics, remote sensing, and surveillance equipment is dependent upon the availability of remote power. While batteries can sometimes fulfill this role over short time intervals, batteries are often undesirable due to their fini ... Full text Cite

Design and experimental study of a Nonlinear Energy Sink coupled to an electromagnetic energy harvester

Journal Article Journal of Sound and Vibration · December 22, 2018 Nonlinear vibration absorbers, commonly referred to as Nonlinear Energy Sinks (NESs), have been the object of several theoretical and experimental studies over the past decade. This work illustrates the theoretical design and experimental realization of a ... Full text Cite

Automating neurosurgical tumor resection surgery: Volumetric laser ablation of cadaveric porcine brain with integrated surface mapping.

Journal Article Lasers Surg Med · December 2018 OBJECTIVE: Current surgical instruments for soft tissue resection including neurosurgical procedures rely on the accuracy and precision of the human operator and are fundamentally constrained by the human hand. Automated surgical action with the integratio ... Full text Link to item Cite

Analytical Method for Stroboscopically Sampling General Periodic Functions with Arbitrary Frequency Sweep Rates

Journal Article Journal of Vibration and Acoustics · December 1, 2018 Parameter sweeps are commonly used to explore the behavior of dynamical systems. This paper derives exact solutions for the instances in time to stroboscopically sample the response of a dynamical system subject to varying input excitations. This work will ... Full text Cite

Stability of coupled human and stand-up paddle board

Journal Article Sports Engineering · December 1, 2018 This study investigates the rider stability on a stand-up paddle board (SUP) based on board dimensions, rider body parameters, and skill level using a buoyant body dynamics approach. For this study, the system of a rider standing on an SUP is modeled as a ... Full text Cite

Passive subharmonic elimination

Journal Article Applied Physics Letters · October 1, 2018 This paper investigates an approach to passively eliminate subharmonic responses in nonlinear oscillators forced at resonance. A general framework is developed for identifying asymptotic levels where parameter values can be passively tuned to achieve dynam ... Full text Cite

Sample Entropy of Speed Power Spectrum as a Measure of Laparoscopic Surgical Instrument Trajectory Smoothness.

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · July 2018 In this study the complexity of the speed power spectrum is assessed as a metric for measuring trajectory smoothness. There are a variety of published methods for analyzing trajectory smoothness but many lack validity. This preliminary study took an inform ... Full text Link to item Cite

Increasing viability of nonlinear energy harvesters by adding an excited dynamic magnifier

Journal Article Journal of Intelligent Material Systems and Structures · April 1, 2018 Dynamic magnifiers and coupled harvester arrays are two strategies that have been developed over the past decade to improve the peak power and bandwidth of energy harvesters. However, both of these methods come with drawbacks. Dynamic magnifiers require re ... Full text Cite

Dynamics of unforced and vertically forced rocking elliptical and semi-elliptical disks

Journal Article Journal of Sound and Vibration · March 17, 2018 This paper presents the results of an investigation on the dynamics of unforced and vertically forced rocking elliptical and semi-elliptical disks. The full equation of motion for both rocking disks is derived from first principles. For unforced behavior, ... Full text Cite

A dynamical systems approach for the submaximal prediction of maximum heart rate and maximal oxygen uptake

Journal Article Sports Engineering · March 1, 2018 This study examines the viability of utilizing a dynamical system model and heuristic parameter estimation algorithm to make predictions for maximum heart rate (HR max) and maximal oxygen uptake (V ˙ O 2 max) using data collected from a submaximal testing ... Full text Cite

On the manifestation of coexisting nontrivial equilibria leading to potential well escapes in an inhomogeneous floating body

Journal Article Physica D: Nonlinear Phenomena · February 15, 2018 This paper examines the bifurcation and stability behavior of inhomogeneous floating bodies, specifically a rectangular prism with asymmetric mass distribution. A nonlinear model is developed to determine the stability of the upright and tilted equilibrium ... Full text Cite

Optimized path planning for soft tissue resection via laser vaporization

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2018 Robotic and robotic-assisted surgeries are becoming more prevalent with the promise of improving surgical outcomes through increased precision, reduced operating times, and minimally invasive procedures. The handheld laser scalpel in neurosurgery has been ... Full text Cite

Snap-through twinkling energy generation through frequency up-conversion

Journal Article Journal of Sound and Vibration · July 7, 2017 A novel experimental energy harvester is investigated for its energy harvesting capability by frequency up-conversion using snap-through structures. In particular, a single-degree-of-freedom (SDOF) experimental energy harvester model is built using a snap- ... Full text Cite

Demonstration of tunable energy propagation using magneto-mechanical oscillator arrays

Conference Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS) · February 23, 2017 This work reports, for the first time, a MEMS testbed platform that not only demonstrates complex energy propagation behaviors in periodic arrays of magnetically coupled mechanical oscillators, but also a technique to alter those behaviors externally, afte ... Full text Cite

A nonlinear model for the characterization and optimization of athletic training and performance

Journal Article Biomedical Human Kinetics · February 1, 2017 Study aim: Mathematical models of the relationship between training and performance facilitate the design of training protocols to achieve performance goals. However, current linear models do not account for nonlinear physiological effects such as saturati ... Full text Cite

Modeling and predicting heart rate dynamics across a broad range of transient exercise intensities during cycling

Journal Article Sports Engineering · June 1, 2016 Prior studies have investigated heart rate dynamics from a variety of perspectives, but are often inadequate for predicting heart rate responses across a broad range of transient exercise intensities. The aim of this study was to develop a nonlinear model ... Full text Cite

Theoretical and experimental analysis of bifurcation induced passive bandgap reconfiguration

Conference Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2016 This paper presents a theoretical analysis and experimental validation of passively reconfigurable bandgaps in a 1D chain of oscillators. Nonlinearities in the system result in a morphing of the bandgap structure when the excitation amplitude passes a cert ... Full text Cite

Utilizing a blending function to improve nonlinear frequency response predictions for a pendulum system

Conference Proceedings of the ASME Design Engineering Technical Conference · January 1, 2016 This paper investigates the use of blending functions to improve nonlinear frequency response predictions for a pendulum system. The harmonic balance method is used to generate approximate analytical solutions for the amplitude-dependent natural frequency ... Full text Cite

Sensitivity of final field position to the punt initial conditions in American football

Conference Proceedings of the ASME Design Engineering Technical Conference · January 1, 2016 The starting field position is often a deciding factor in an American football game. In the case of a defensive stop, a kick, known as a punt, is used to give the receiving team a field position that is more advantageous to the kicking team when possession ... Full text Cite

Static stability analysis of a floating rectangular prism

Conference Proceedings of the ASME Design Engineering Technical Conference · January 1, 2016 This paper examines the static stability of a floating rectangular prism. A nonlinear model is developed to determine the stability of the upright and tilted equilibria positions as a function of the vertical location of the prism's center of mass. These e ... Full text Cite

Quenching chatter instability in turning process with a vibro-impact nonlinear energy sink

Journal Article Journal of Sound and Vibration · October 27, 2015 This paper investigates the passive control of chatter instability in turning processes using a vibro-impact nonlinear energy sink (NES). The workpiece is assumed to be rigid and the tool is flexible. A dynamical model including a nonlinear cutting law is ... Full text Cite

Investigation of wave propagation phenomena in microfabricated arrays of nonlinearly coupled oscillators

Conference 2015 Transducers - 2015 18th International Conference on Solid-State Sensors, Actuators and Microsystems, TRANSDUCERS 2015 · August 5, 2015 We demonstrate a MEMS platform for the investigation of energy propagation behavior in an array of nonlinearly coupled oscillators. The long-term objective is to experimentally demonstrate behaviors that have, until recently, only been theorized to occur i ... Full text Cite

Dynamics of rocking semicircular, parabolic, and semi-elliptical disks: Equilibria, stability, and natural frequencies

Journal Article Journal of Vibration and Acoustics · August 1, 2015 This paper performs a theoretical and experimental investigation of the natural frequency and stability of rocking semicircular, parabolic, and semi-elliptical disks. Horace Lamb's method for deriving the natural frequency of an arbitrary rocking disk is a ... Full text Cite

Analysis of stability differences in road and time trial bicycles with instantaneous and delayed control

Journal Article Sports Engineering · June 1, 2015 Bicycle stability has been of interest to dynamicists and athletes since before J. W. Whipple described the canonical model for bicycle motion in 1899. Since then, the subject has fascinated many who sought to find a simple way to describe the essence of s ... Full text Cite

Modeling heart rate dynamics in response to changes in exercise intensity

Conference Proceedings of the ASME Design Engineering Technical Conference · January 1, 2015 This paper develops a nonlinear mathematical model to describe the heart rate response of an individual during cycling. The model is able to account for the fluctuations of an individual's heart rate while they participate in exercise that varies in intens ... Full text Cite

Investigation of wave propagation behavior in magnetically coupled mems oscillators

Conference Proceedings of the ASME Design Engineering Technical Conference · January 1, 2015 This paper investigates the dynamic behavior of a 1D array of magnetically coupled MEMS oscillators. To facilitate future research and innovation, this paper details the model used to predict wave propagation behavior in the microfabricated array. The inve ... Full text Cite

Dynamics of an eccentric disk on a curved surface

Journal Article Physica D: Nonlinear Phenomena · January 1, 2014 This paper investigates the dynamic behavior of an eccentric disk rolling on a curve of arbitrary shape and then on a curve defined as a cubic function. Comparisons are made to a disk without eccentricity and the related point mass approximation. The curve ... Full text Cite

Experimental investigation of colored noise in stochastic resonance of a bistable beam

Journal Article Physica D: Nonlinear Phenomena · January 1, 2014 This paper describes an experimental investigation of stochastic resonance in a bistable, composite beam excited by colored noise. Experimental results for average up-crossing period, spectral power amplification (SPA), and signal-to-noise ratio (SNR) are ... Full text Cite

Discussion: "On the role of nonlinearities in vibratory energy harvesting: A critical review and discussion" (Daqaq, M., Masana, R., Erturk, A., and Dane Quinn, D., 2014, ASME Appl. Mech. Rev., 66(4), p. 040801)

Journal Article Applied Mechanics Reviews · January 1, 2014 The authors have written a nice review on the purposeful use of nonlinearity in vibratory energy harvesting. The current limitations of batteries and advancements in low-power electronic devices are identified as two motivating factors for energy harvestin ... Full text Cite

Minimizing error in the logarithmic decrement method through uncertainty propagation

Journal Article Journal of Sound and Vibration · January 1, 2014 Logarithmic decrement is a well known approach for estimating the damping ratio from a time history. This paper uses uncertainty propagation to unveil how uncertainties in different quantities can impact damping ratio estimates. More specifically, the trad ... Full text Cite

Experimental investigation of bifurcation induced bandgap reconfiguration

Journal Article Journal of Applied Physics · January 1, 2014 By applying an asymmetric on-site restoring force in a 1D chain of oscillators, we demonstrate experimentally that a morphing in the bandgap structure or passive bandgap reconfiguration can be triggered by an increase in environmental excitation amplitude. ... Full text Cite

Investigation of rocking semicircular and parabolic disk equilibria, stability, and natural frequencies

Conference Proceedings of the ASME Design Engineering Technical Conference · January 1, 2014 This paper performs a theoretical and experimental investigation of the natural frequency and stability of rocking semicircular and parabolic disks. Horace Lamb's method for deriving the natural frequency of an arbitrary rocking disk is applied to two shap ... Full text Cite

Two-dimensional nonlinear analysis of an untethered spherical buoy due to wave loading

Journal Article Journal of Computational and Nonlinear Dynamics · December 2, 2013 The horizontal and vertical motions of a nonlinear spherical buoy, excited by synthetic ocean waves within a wave flume, is numerically and experimentally investigated. First, fluid motion in the wave tank is described using Airy's theory, and the forces o ... Full text Cite

Delayed feedback control of chaos for arbitrary delays analyzed with the spectral element method

Journal Article International Journal of Dynamics and Control · December 1, 2013 The spectral element approach is applied for the first time to the control of chaos with arbitrary control delays. Three important cases are explored using the spectral approach: half-period delayed feedback control (DFC), control loop latency in DFC and e ... Full text Cite

Passive band-gap reconfiguration born from bifurcation asymmetry

Journal Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics · November 7, 2013 Current periodic structures are constrained to have fixed energy transmission behavior unless active control or component replacement is used to alter their wave propagation characteristics. The introduction of nonlinearity to generate multiple stable equi ... Full text Cite

Broadband energy harvesting from a bistable potential well

Chapter · September 1, 2013 This chapter describes recent research on the use of a bistable oscillator, in lieu of the more common choice of using a linear oscillator, for energy harvesting. The chapter progresses from the elementary theory for the potential well escape problem to an ... Full text Cite

Dynamics of a horizontal pendulum driven by high-frequency rocking

Journal Article Journal of Sound and Vibration · August 9, 2013 This paper investigates the dynamics of a horizontal pendulum subjected to high frequency rocking. The method of direct partition of motion is applied to the governing equation to separate the fast and slow dynamics. It is shown that two stable equilibria ... Full text Cite

On the use of weighting matrices to improve harmonic balance parameter identification results

Journal Article Journal of Sound and Vibration · June 10, 2013 This paper investigates the use of weighting matrices to improve the harmonic balance identification (HBID) method for identifying nonlinear oscillators. While the notation for adding weighting matrices has been previously introduced, typical strategies fo ... Full text Cite

Application of the Liapunov-Floquet transformation to differential equations with time delay and periodic coefficients

Journal Article JVC/Journal of Vibration and Control · March 1, 2013 In this paper, the Liapunov-Floquet transformation (LFT) is applied to a time-periodic delay differential equation (DDE) discretized by the Chebyshev spectral continuous time approximation. The proposed combined approach allows for the stability and time-r ... Full text Cite

Effect of rider position on bicycle stability

Conference ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) · January 1, 2013 Bicycle stability has been of interest to dynamicists and athletes since before J. W. Whipple described the canonical model for bicycle motion in 1899. Since then, the subject has fascinated many who sought to find a simple way to describe the essence of s ... Full text Cite

Energy absorption in a 1D array of axially aligned pendulums with linear torsional coupling

Journal Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) · January 1, 2013 This paper evaluates wave propagation and energy absorption in a 1D array of axially aligned pendulums under various forms of base excitation. In the system studied, each pair of pendulums comprising a single unit cell is connected through linear torsional ... Full text Cite

Cycling aerodynamics: The effect of rider position on aerodynamic drag

Journal Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) · January 1, 2013 Competitive cyclists seek to maximize their efficiency by minimizing the influence of resistive forces. At the high speeds maintained during competition, aerodynamic drag is the primary resistive force. This paper investigates the influence of a cyclist's ... Full text Cite

A spectral element approach for the stability analysis of time-periodic delay equations with multiple delays

Journal Article Communications in Nonlinear Science and Numerical Simulation · January 1, 2013 This paper describes a general spectral element approach to study the stability of multiple time delay systems (MTDS). We show, for the first time, how this approach can be applied to periodic MTDS where the delays and the period are incommensurate. In con ... Full text Cite

Uncertainty propagation in the band gap structure of a 1D array of magnetically coupled oscillators

Journal Article Journal of Vibration and Acoustics · January 1, 2013 The propagation constant technique has previously been used to predict band gap regions in linear oscillator chains by solving an eigenvalue problem for frequency in terms of a wave number. This paper describes a method by which selected design parameters ... Full text Cite

Transition curves in a parametrically excited pendulum with a force of elliptic type

Journal Article Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences · December 8, 2012 This article investigates the equilibria and stability of a pendulum when the support has a prescribed motion defined by an elliptic function. Stability charts are generated in the parameter plane for different values of the elliptic function modulus. Nume ... Full text Cite

Spectral element method and the delayed feedback control of chaos

Journal Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics · October 31, 2012 A spectral element approach is introduced to determine the Floquet exponents (FEs) of unstable periodic orbits (UPOs) stabilized by extended delayed feedback control (EDFC). The spectral approach does not require solving time-dependent eigenproblems that e ... Full text Cite

Potential well metamorphosis of a pivoting fluid-filled container

Journal Article Physica D: Nonlinear Phenomena · October 1, 2012 This paper investigates the stability of a pivoting cylindrical container that is slowly filled with fluid. The action of filling the container with fluid causes the system's potential energy to evolve and modify the stability of equilibria. We analyze the ... Full text Cite

Uncertainty in performance for linear and nonlinear energy harvesting strategies

Journal Article Journal of Intelligent Material Systems and Structures · September 1, 2012 Vibrational energy harvesters are often linear mass-spring-damper-type devices, which have their resonant frequency tuned to the dominant vibration frequency of their host environment. As such, they can be highly sensitive to uncertainties, which may arise ... Full text Cite

On the comparison of semi-analytical methods for the stability analysis of delay differential equations

Journal Article Journal of Sound and Vibration · August 13, 2012 This paper provides the first comparison of the semi-discretization, spectral element, and Legendre collocation methods. Each method is a technique for solving delay differential equations (DDEs) as well as determining regions of stability in the DDE param ... Full text Cite

Harmonic balance analysis of the bistable piezoelectric inertial generator

Journal Article Journal of Sound and Vibration · July 16, 2012 This paper applies the method of Harmonic Balance to analytically predict the existence, stability, and influence of parameter variations on the intrawell and interwell oscillations of bistable piezoelectric inertial generator. Existing work on the bistabl ... Full text Cite

Control-based continuation for investigating nonlinear experiments

Journal Article JVC/Journal of Vibration and Control · April 1, 2012 In this paper we present a systematic experimental study of two one-degree-of-freedom nonlinear devices using the newly introduced control-based continuation method of Sieber and Krauskopf. By considering hardening, softening and bistable spring characteri ... Full text Cite

Melnikov theoretic methods for characterizing the dynamics of the bistable piezoelectric inertial generator in complex spectral environments

Journal Article Physica D: Nonlinear Phenomena · March 15, 2012 Piezoelectric energy harvesters exploiting strong mechanical nonlinearities exhibit intrinsic suitability for one of several modern challenges in vibratory energy harvesting: consistent kinetic performance in the presence of broadband environmental excitat ... Full text Cite

Linear and nonlinear electromagnetic coupling models in vibration-based energy harvesting

Journal Article Journal of Sound and Vibration · February 13, 2012 This paper investigates the response of an energy harvester that uses electromagnetic induction to convert ambient vibration into electrical energy. A unique aspect of the present study is the comparison of the systems response behavior when either a linea ... Full text Cite

Potential well escape of an eccentric disk

Journal Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) · January 1, 2012 This paper investigates the dynamic behavior of an eccentric disk rolling on a curve of arbitrary shape and then on a curve defined as a cubic function. Comparisons are made to a disk with no eccentricity and the related point mass approximation. The curve ... Full text Cite

Analysis of the bistable piezoelectric inertial generator by the harmonic balance method

Journal Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) · January 1, 2012 This paper analytically predicts the existence, stability, and changes due to parameter variations on the different oscillations of a bistable piezoelectric generator. Existing work on this type of system has assumed linear piezoelectric behavior and linea ... Full text Cite

Experimental study of human walking to running dynamics with applications to energy harvesting

Journal Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) · January 1, 2012 The nonlinear dynamics of a runner are reported here. Image processing software is used obtain experimental data of the 2-D leg motion of the athlete. The available power that the athlete creates from this motion is calculated for multiple speeds. The mult ... Full text Cite

Dynamics of a gravity car race with application to the Pinewood Derby

Journal Article Mechanical Sciences · January 1, 2012 This paper investigates the underlying physics of a gravity car race. This work seeks to provide a sound theoretical basis to elucidate the design considerations that maximize performance while simultaneously dispelling false assertions that may arise from ... Full text Cite

Analytic Bounds for Instability Regions in Periodic Systems With Delay via Meissner's Equation

Journal Article JOURNAL OF COMPUTATIONAL AND NONLINEAR DYNAMICS · January 2012 A method for obtaining analytic bounds for period doubling and cyclic fold instability regions in linear time-periodic systems with piecewise constant coefficients and time delay is suggested. The method is based on the use of transition matrices for Meiss ... Full text Cite

Nonlinear nonconservative behavior and modeling of piezoelectric energy harvesters including proof mass effects

Journal Article Journal of Intelligent Material Systems and Structures · January 1, 2012 Nonlinear piezoelectric effects in flexural energy harvesters have recently been demonstrated for drive amplitudes well within the scope of anticipated vibration environments for power generation. In addition to strong softening effects, steady-state oscil ... Full text Cite

Investigation of period-doubling islands in milling with simultaneously engaged helical flutes

Journal Article Journal of Vibration and Acoustics · January 1, 2012 This paper investigates the stability of a milling process with simultaneously engaged flutes using the state-space TFEA and Chebyshev collocation methods. In contrast to prior works, multiple flute engagement due to both the high depth of cut and high ste ... Full text Cite

Periodic solutions of nonlinear delay differential equations using spectral element method

Journal Article Nonlinear Dynamics · January 1, 2012 We extend the temporal spectral element method further to study the periodic orbits of general autonomous nonlinear delay differential equations (DDEs) with one constant delay. Although we describe the approach for one delay to keep the presentation clear, ... Full text Cite

Refining the method of averaging for a more accurate analytical approximation to the behaviors of a damped pendulum

Journal Article Proceedings of the ASME Design Engineering Technical Conference · January 1, 2012 KBM averaging is a widely used technique in the analysis of nonlinear dynamical systems. The KBM method allows complex systems to be approximated as perturbations of simple harmonic oscillator. In many cases, such as in otherwise linear systems with variou ... Full text Cite

Fractal boundary explorations for a nonlinear two degree-of-freedom system

Journal Article Proceedings of the ASME Design Engineering Technical Conference · January 1, 2012 This paper explores a two degree-of-freedom nonlinearly coupled system with two distinct potential wells. The system consists of a pair of linear mass-spring-dampers with a non-linear, mechanical coupling between them. This nonlinearity creates fractal bou ... Full text Cite

Parameter identification of a nonlinear beam energy harvester

Journal Article Proceedings of the ASME Design Engineering Technical Conference · January 1, 2012 This paper describes the application of the harmonic balance parameter identification method to beam energy harvesters. The method is applied to weakly nonlinear and nonlinear, bistable fixed-free piezoelectric beams with tip masses. It is shown that only ... Full text Cite

Using the mass ratio to induce band gaps in a 1d array of nonlinearly coupled oscillators

Journal Article Proceedings of the ASME Design Engineering Technical Conference · January 1, 2012 A one dimensional system of nonlinearly coupled magnetic oscillators has been studied. After deriving the equations of motion for each oscillator, the system is linearized about a stable equilibrium and studied using an assumed solution form for a travelin ... Full text Cite

Dynamics of a rocking horizontal pendulum under high frequency excitation

Journal Article Proceedings of the ASME Design Engineering Technical Conference · January 1, 2012 In this work, we investigate the effect of high frequency excitation on a pendulum positioned at a given distance from a tilted platform. The tilted platformis subjected to high frequency excitation. The method of direct partition of motion is applied to t ... Full text Cite

Aeroelastic limit cycles as a small scale energy source

Journal Article Proceedings of the ASME Design Engineering Technical Conference · December 1, 2011 Nonlinear limit cycle oscillations of an aeroelastic energy harvester are exploited for enhanced piezoelectric power generation from aerodynamic flows. Specifically, a flexible beam with piezoelectric laminates is excited by a uniform axial flow field in a ... Full text Cite

Comparative study of semi-analytical methods for the stability analysis of delay differential equations

Journal Article Proceedings of the ASME Design Engineering Technical Conference · December 1, 2011 This paper describes and compares the zeroth-order semi-discretization, spectral element, and Legendre collocation methods. Each method is a technique for solving delay differential equations (DDEs) as well as determining regions of stability in the DDE pa ... Full text Cite

Horizontal pendulum with sudden changes in platform tilt

Journal Article Proceedings of the ASME Design Engineering Technical Conference · December 1, 2011 The equations of motion for a horizontal pendulum mounted to a rocking platform are developed. Equilibrium conditions are found as a function of the platform tilt angle. The equations are transformed to describe motion about the shifting equilibrium point, ... Full text Cite

Comparison of linear and nonlinear electromagnetic coupling models for a linear oscillator

Journal Article Proceedings of the ASME Design Engineering Technical Conference · December 1, 2011 This paper examines the modeling and behavior of two forms of electromagnetic coupling with a linear oscillator. With coupling as either a linear or a nonlinear term dependent on position, analytical results were derived and numerical simulations performed ... Full text Cite

Stability of a pivoting fluid-filled container

Journal Article Proceedings of the ASME Design Engineering Technical Conference · December 1, 2011 This paper investigates the stability of a pivoting cylindrical container that is slowly filled with fluid. The stability of the upright and tilt angle equilibria is studied by using the Lagrange-Dirichlet theorem. The potential energy of the system is giv ... Full text Cite

Experimental and numerical investigations of an untethered, nonlinear spherical buoy in a wave tank

Journal Article Proceedings of the ASME Design Engineering Technical Conference · December 1, 2011 The horizontal and vertical motions of a spherical buoy, excited by synthetic ocean waves within a wave flume, is numerically and experimentally investigated. First, fluid motion in the wave tank is described using Airy's theory, and the forces on the buoy ... Full text Cite

Power extraction from aeroelastic limit cycle oscillations

Journal Article Journal of Fluids and Structures · November 1, 2011 Nonlinear limit cycle oscillations of an aeroelastic energy harvester are exploited for enhanced piezoelectric power generation from aerodynamic flows. Specifically, a flexible beam with piezoelectric laminates is excited by a uniform axial flow field in a ... Full text Cite

Stability of delay integro-differential equations using a spectral element method

Journal Article Mathematical and Computer Modelling · November 1, 2011 This paper describes a spectral element approach for studying the stability of delay integro-differential equations (DIDEs). In contrast to delay differential equations (DDEs) with discrete delays that act point-wise, the delays in DIDEs are distributed ov ... Full text Cite

A spectral element approach for the stability of delay systems

Journal Article International Journal for Numerical Methods in Engineering · August 12, 2011 We describe a spectral element approach to study the stability and equilibria solutions of Delay differential equations (DDEs). In contrast to the prototypical temporal finite element analysis (TFEA), the described spectral element approach admits spectral ... Full text Cite

Experimental investigation of a post-buckled piezoelectric beam with an attached central mass used to harvest energy

Journal Article Proceedings of the Institution of Mechanical Engineers. Part I: Journal of Systems and Control Engineering · June 1, 2011 Recent advances in wireless electronics have outpaced concurrent advances in battery technology, and this has led to the emergence of vibrational energy harvesting as an alternative source of energy for low-power wireless devices. In particular, piezoelect ... Full text Cite

Using information to generate derivative coordinates from noisy time series

Journal Article Communications in Nonlinear Science and Numerical Simulation · January 1, 2011 This paper describes an approach for recovering a signal, along with the derivatives of the signal, from a noisy time series. To mimic an experimental setting, noise was superimposed onto a deterministic time series. Data smoothing was then used to success ... Full text Cite

A multi-interval Chebyshev collocation approach for the stability of periodic delay systems with discontinuities

Journal Article Communications in Nonlinear Science and Numerical Simulation · January 1, 2011 This paper investigates the stability of periodic delay systems with non-smooth coefficients using a multi-interval Chebyshev collocation approach (MIC). In this approach, each piecewise continuous interval is expanded in a Chebyshev basis of the first ord ... Full text Cite

Potential well shaping through the use of impact barriers for broadband electroelastic energy harvesting

Journal Article ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2011 · January 1, 2011 Many recent advances in electroelastic energy harvesting have benefitted from the use of nonlinear effects that reshape the potential well of the device and lead to bandwidth improvement. In this letter, the merits of using impact barriers for potential we ... Full text Cite

Experimental investigations of a bistable energy harvester

Journal Article Conference Proceedings of the Society for Experimental Mechanics Series · January 1, 2011 This paper investigates the design and analysis of a nonlinear energy harvester that uses magnet interactions to create an inertial generator with a bistable potential well. The motivating hypothesis for this work was that nonlinear behavior could be used ... Full text Cite

Resonant manifestation of intrinsic nonlinearity within electroelastic micropower generators

Journal Article Applied Physics Letters · December 20, 2010 This letter investigates the nonlinear response of a bimorph energy harvester comprised of lead zirconate titanate (PZT-5A) laminates. For near resonant excitations, we demonstrate significant intrinsic nonlinear behavior despite geometrically linear motio ... Full text Open Access Cite

Investigations of natural frequencies and vibration mode shapes for a post-buckled beam with different attached masses

Journal Article ASME 2010 Dynamic Systems and Control Conference, DSCC2010 · December 1, 2010 This paper considers the theoretical response of a baseexcited post-buckled beam. A mass that can be varied was attached to the midspan of the clamped-clamped beam. The theoretical model for the post-buckled beam was first investigated by applying the exte ... Full text Cite

Nonlinear piezoelectricity in electroelastic energy harvesters: Modeling and experimental identification

Journal Article Journal of Applied Physics · October 1, 2010 We propose and experimentally validate a first-principles based model for the nonlinear piezoelectric response of an electroelastic energy harvester. The analysis herein highlights the importance of modeling inherent piezoelectric nonlinearities that are n ... Full text Open Access Cite

On the nonlinear electromagnetic coupling between a coil and an oscillating magnet

Journal Article Journal of Physics D: Applied Physics · July 16, 2010 The electromagnetic induction of voltage across a coil due to the motion of a magnet is among the fundamental problems of physics, and it has a broad range of practical applications. While Maxwell's equations exactly describe this phenomenon, the physical ... Full text Open Access Cite

On the dynamic response of beams with multiple geometric or material discontinuities

Journal Article Mechanical Systems and Signal Processing · July 1, 2010 An analytic framework is developed for determining closed form expressions for the natural frequencies, mode shapes, and frequency response function for Euler-Bernoulli beams with any number of geometric or material discontinuities. The procedure uses a co ... Full text Cite

A closed form mechanistic cutting force model for helical peripheral milling of ductile metallic alloys

Journal Article International Journal of Machine Tools and Manufacture · June 1, 2010 A closed form mechanistic model is developed for cutting forces in helical peripheral milling (endmilling) of ductile metallic alloys. This paper presents an alternative derivation, using the frontal chip area, to describe two series of cutting force expre ... Full text Cite

Stability of Delay Equations Written as State Space Models

Journal Article JOURNAL OF VIBRATION AND CONTROL · June 2010 In this paper we describe a new approach to examine the stability of delay differential equations that builds upon prior work using temporal finite element analysis. In contrast to previous analyses, which could only be applied to second-order delay differ ... Full text Cite

Nonlinear dynamics for broadband energy harvesting: Investigation of a bistable piezoelectric inertial generator

Journal Article Physica D: Nonlinear Phenomena · May 15, 2010 Vibration energy harvesting research has largely focused on linear electromechanical devices excited at resonance. Considering that most realistic vibration environments are more accurately described as either stochastic, multi-frequency, time varying, or ... Full text Cite

On the performance and resonant frequency of electromagnetic induction energy harvesters

Journal Article Journal of Sound and Vibration · April 26, 2010 This paper investigates the linear response of an archetypal energy harvester that uses electromagnetic induction to convert ambient vibration into electrical energy. In contrast with most prior works, the influence of the circuit inductance is not assumed ... Full text Cite

Investigations of a nonlinear energy harvester with a bistable potential well

Journal Article Journal of Sound and Vibration · April 26, 2010 This paper investigates a nonlinear energy harvester that uses magnetic interactions to create an inertial generator with a bistable potential well. The motivating hypothesis for this work was that nonlinear behavior could be used to improve the performanc ... Full text Cite

Fuzzy stability analysis of regenerative chatter in milling

Journal Article Journal of Sound and Vibration · April 12, 2010 During machining, unstable self-excited vibrations known as regenerative chatter can occur, causing excessive tool wear or failure, and a poor surface finish on the machined workpiece. Consequently it is desirable to predict, and hence avoid the onset of t ... Full text Cite

Analysis of milling dynamics for simultaneously engaged cutting teeth

Journal Article Journal of Sound and Vibration · March 1, 2010 This paper investigates the stability of a milling process with simultaneously engaged teeth and contrasts it to prior work for a single tooth in the cut. The stability analyses are performed with the Chebyshev collocation method and the state-space TFEA t ... Full text Cite

Comparison between collocation methods and spectral element approach for the stability of periodic delay systems ?

Journal Article IFAC Proceedings Volumes (IFAC-PapersOnline) · January 1, 2010 This paper compares two methods that are commonly used to study the stability of delay systems. The first is a collocation technique while the second is a spectral element approach which uses the weighted residual method. Two distributions of the collocati ... Full text Cite

Engaging nonlinearity for enhanced vibratory energy harvesting

Journal Article Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference · January 1, 2010 This article discusses inherent and purposefully integrated nonlinear phenomena within electroelastic energy harvesting devices. Specifically, the authors discuss recent results highlighting the importance of modeling nonlinear piezoelectricity and review ... Full text Cite

On the manifestation and influence of material nonlinearity in electroelastic power generators

Journal Article ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2010 · January 1, 2010 We investigate and model observed nonlinear piezoelectric response of an electroelastic energy harvester. The model employed is a simplified version of the fully nonlinear model proposed by Stanton and Mann [1] since the mechanical oscillations of the expe ... Full text Cite

Comparison of linear and nonlinear energy harvesting strategies with uncertainty

Conference Proceedings of ISMA 2010 - International Conference on Noise and Vibration Engineering, including USD 2010 · January 1, 2010 The present article investigates how linear and nonlinear energy harvesting strategies are affected by uncertainties. Comparisons are made between a prototypical harvester - one that uses a linear oscillator and electromagnetic induction for energy convers ... Cite

Stability analysis and control of linear periodic delayed systems using Chebyshev and temporal finite element methods

Journal Article · December 1, 2009 In this chapter, a brief literature review is provided together with detailed descriptions of the authors' work on the stability and control of systems represented by linear time-periodic delay-differential equations using the Chebyshev and temporal finite ... Full text Cite

Milling bifurcations: A numerical study

Journal Article Proceedings of the ASME Design Engineering Technical Conference · December 1, 2009 In this work, a new model for predicting the dynamic behavior of the milling process is developed. Modeling of the discontinuous cutting forces now takes into account the motion of the cutting tool. The chip thickness is determined by using a search algori ... Full text Cite

Harvesting energy from the nonlinear oscillations of a bistable piezoelectric inertial energy generator

Journal Article Proceedings of the ASME Design Engineering Technical Conference · December 1, 2009 Piezoelectric materials constitute an efficient transduction medium for passive power generation from ambient vibrations. As such, the unimorph and bimorph piezoelectric laminate linear beam is a prolifically researched energy harvesting device. The linear ... Full text Cite

Self-excited vibrations in a delay oscillator: Application to milling with simultaneously engaged helical flutes

Journal Article Proceedings of the ASME Design Engineering Technical Conference · December 1, 2009 This paper investigates the stability of a milling process with simultaneously engaged flutes by extending the state-space temporal finite elements method. In contrast to prior works, multiple flute engagement due to both a high depth of cut and a high ste ... Full text Cite

A state-space temporal finite element approach for stability investigations of delay equations

Journal Article Proceedings of the ASME Conference on Smart Materials, Adaptive Structures and Intelligent Systems 2009, SMASIS2009 · December 1, 2009 This paper describes a new approach to examine the stability of delay differential equations that builds upon prior work using temporal finite element analysis. In contrast to previous analyses, which could only be applied to second order delay differentia ... Full text Cite

Reversible hysteresis for broadband magnetopiezoelastic energy harvesting

Journal Article Applied Physics Letters · November 10, 2009 We model and experimentally validate a nonlinear energy harvester capable of bidirectional hysteresis. In particular, both hardening and softening response within the quadratic potential field of a power generating piezoelectric beam (with a permanent magn ... Full text Cite

Explanation for low-speed stability increases in machining: Application of a continuous delay model

Journal Article 2008 Proceedings of the ASME Dynamic Systems and Control Conference, DSCC 2008 · October 19, 2009 This paper investigates the analysis of delay integro-differential equations to explain the increased stability behavior commonly observed at low cutting speeds in machining processes. In the past, this improved stability has been attributed to the energy ... Cite

Increased stability of low-speed turning through a distributed force and continuous delay model

Journal Article Journal of Computational and Nonlinear Dynamics · October 1, 2009 This paper investigates the increased stability behavior commonly observed in low-speed machining. In the past, this improved stability has been attributed to the energy dissipated by the interference between the workpiece and the tool relief face. In this ... Full text Cite

Energy criterion for potential well escapes in a bistable magnetic pendulum

Journal Article Journal of Sound and Vibration · June 19, 2009 This paper examines the dynamic behavior of a bistable experiment comprised a pendulum and two magnets. Investigations focus on determining when the oscillations about one equilibrium will overcome an adjacent potential barrier and escape to a neighboring ... Full text Cite

An energy-balance approach for oscillator parameter identification

Journal Article Journal of Sound and Vibration · March 20, 2009 An energy-based approach for parametric nonlinear identification was investigated. The presented method uses an energy balance on the oscillator governing equations for identification purposes, thus requiring the availability of the position and velocity s ... Full text Cite

Energy harvesting from the nonlinear oscillations of magnetic levitation

Journal Article Journal of Sound and Vibration · January 9, 2009 This paper investigates the design and analysis of a novel energy harvesting device that uses magnetic levitation to produce an oscillator with a tunable resonance. The governing equations for the mechanical and electrical domains are derived to show the d ... Full text Cite

Milling optimisation of removal rate and accuracy with uncertainty: Part 2: Parameter variation

Journal Article International Journal of Materials and Product Technology · January 1, 2009 Milling models provide tools for estimating stability and surface location error. Existing models are deterministic, though inherent variations in the model inputs propagate to uncertainty in the model outputs. In this paper the experimental procedures use ... Full text Cite

Milling optimisation of removal rate and accuracy with uncertainty: Part 1: Parameter selection

Journal Article International Journal of Materials and Product Technology · January 1, 2009 Successful implementation of milling requires the selection of appropriate operating parameters. In this paper a semi-analytical modeling approach and multi-objective optimisation are used to select optimum spindle speed and axial depth. The trade-off curv ... Full text Cite

Observation and investigation of a non-monotonic period function for an impact oscillator

Journal Article Communications in Nonlinear Science and Numerical Simulation · January 1, 2009 A mathematical model for a bench-top impact oscillator (a steel pendulum and an aluminum barrier) that incorporates Hertzian contact is analyzed, and predictions derived from our model are compared with experimental data. We report our discovery of a new e ... Full text Cite

Analytical prediction of chatter stability for variable pitch and variable helix milling tools

Journal Article Journal of Sound and Vibration · November 11, 2008 Regenerative chatter is a self-excited vibration that can occur during milling and other machining processes. It leads to a poor surface finish, premature tool wear, and potential damage to the machine or tool. Variable pitch and variable helix milling too ... Full text Cite

On the chatter frequencies of milling processes with runout

Journal Article International Journal of Machine Tools and Manufacture · August 1, 2008 The detection of undesirable vibrations in milling operations is an important task for the manufacturing engineer. While monitoring the frequency spectra is usually an efficient approach for chatter detection, since these spectra typically have a clear and ... Full text Cite

An experimental study of subcritical bifurcations in milling

Journal Article 2007 Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, DETC2007 · June 13, 2008 The focus of the current paper is an experimental investigation of subcritical bifurcations in milling. Several researchers have reported results indicating that the secondary Hopf bifurcations of turning processes are subcritical. However, fewer results a ... Full text Cite

Harmonic balance nonlinear identification of a capacitive dual-backplate MEMS microphone

Journal Article Journal of Microelectromechanical Systems · June 1, 2008 This paper describes the application of a nonlinear identification method to extract model parameters from the steady-state response of a capacitive dual-backplate microelectromechanical systems microphone. The microphone is modeled as a single-degree-of-f ... Full text Cite

Measurement nonlinearity interpreted as material behavior in dynamic nanoindentation

Journal Article Journal of Sound and Vibration · April 8, 2008 This paper explores the errors that may arise in when interpreting dynamic nanoindentation measurements with a linear oscillator model. The work was motivated by an experimental observation that the system's primary resonance can be dramatically altered by ... Full text Cite

Chatter vibration and surface location error prediction for helical end mills

Journal Article International Journal of Machine Tools and Manufacture · March 1, 2008 This paper describes a new theoretical model for the cutting forces of a helical end mill. A specific advantage for the presented model is the convenience in implementing the developed expressions for vibration prediction. Specifically, the presented force ... Full text Cite

Fuzzy stability analysis of milling processes

Conference 23rd International Conference on Noise and Vibration Engineering 2008, ISMA 2008 · January 1, 2008 During machining, unstable self-excited vibrations known as regenerative chatter can occur when the depth of cut is too large. Chatter causes excessive tool wear or failure and a poor surface finish on the machined workpiece, and so it is desirable to pred ... Cite

Using nonlinearity to improve the performance of vibration-Based energy harvesting devices

Conference 7th European Conference on Structural Dynamics, EURODYN 2008 · January 1, 2008 This paper investigates the design and analysis of a novel energy harvesting device. The governing equations for the mechanical and electrical domains are derived to show the designed system reduces to the form of a Duffing oscillator under both static and ... Cite

Uncharted islands of chatter instability in milling

Journal Article International Journal of Machine Tools and Manufacture · 2008 Cite

Surface location error and chatter prediction for helical end mills

Journal Article International Journal of Machine Tools and Manufacture · 2008 Cite

A robust semi-analytical method for calculating the response sensitivity of a time delay system

Journal Article Journal of Vibration and Acoustics · January 1, 2008 It is often necessary to establish the sensitivity of an engineering system's response to variations in the process/control parameters. Applications of the calculated sensitivity include gradient-based optimization and uncertainty quantification, which gen ... Full text Cite

Uncharted islands of chatter instability in milling

Journal Article International Journal Of Machine Tools \& Manufacture · January 2008 This paper provides conclusive evidence that isolated islands of chatter vibration can exist in milling processes. Investigations show these islands are induced by the tool helix angle and act to separate regions of period-doubling and quasi-periodic behav ... Cite

Identification of machine tool chatter for milling operations with runout

Journal Article 14th International Congress on Sound and Vibration 2007, ICSV 2007 · December 1, 2007 Detection of undesired machine tool vibrations during milling operations is an important task for manufacturing engineers. Monitoring of frequency spectra is an efficient tool of chatter detection since these spectra usually have a clear, systematic struct ... Cite

Experimental study of an impact oscillator with viscoelastic and Hertzian contact

Journal Article Nonlinear Dynamics · November 1, 2007 Modeling an impact event is often related to the desired outcome of an impact oscillator study. If the only intent is to study the dynamic behavior of the system, numerous researchers have shown that simpler impact models will often suffice. However, when ... Full text Cite

Stability of a time-delayed system with parametric excitation

Journal Article Journal of Dynamic Systems, Measurement and Control, Transactions of the ASME · March 1, 2007 This paper investigates two different temporal finite element techniques, a multiple element (h-version) and single element (p-version) method, to analyze the stability of a system with a time-periodic coefficient and a time delay. The representative probl ... Full text Cite

Dynamics of milling processes with variable time delay

Journal Article Nonlinear Dynamics · 2007 Cite

Dynamics of milling processes with variable time delays

Journal Article Nonlinear Dynamics · January 1, 2007 A milling-process model with a variable time delay associated with each cutting tooth is presented in this article. The source of this variable time delay is the feed rate. The effect of the feed motion on the entry cutting angle, the exit cutting angle, a ... Full text Cite

Symmetry breaking bifurcations of a parametrically excited pendulum

Journal Article Nonlinear Dynamics · December 1, 2006 This paper examines the bifurcation behavior of a planar pendulum subjected to high-frequency parametric excitation along a tilted angle. Parametric nonlinear identification is performed on the experimental system via an optimization approach that utilizes ... Full text Cite

Closed-form solutions for surface location error in milling

Journal Article International Journal of Machine Tools and Manufacture · October 1, 2006 This paper provides two new analytical solutions for the computation of surface location errors, or part geometry errors that arise due to forced vibrations of the cutting tool, during stable milling. Prior studies of surface location error have applied nu ... Full text Cite

Closed form solutions for the dynamic response of Euler-Bernoulli beams with step changes in cross section

Journal Article Journal of Sound and Vibration · August 8, 2006 This paper provides an analytical solution for the dynamic response of a discontinuous beam with one step change and an aligned neutral axis. The case of free-free boundary conditions is considered to obtain direct frequency response functions due to harmo ... Full text Cite

An empirical approach for delayed oscillator stability and parametric identification

Journal Article Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences · January 1, 2006 This paper investigates a semi-empirical approach for determining the stability of systems that can be modelled by ordinary differential equations with a time delay. This type of model is relevant to biological oscillators, machining processes, feedback co ... Full text Cite

Correcting measurement nonlinearity in dynamic nanoindentation

Journal Article American Society of Mechanical Engineers, Applied Mechanics Division, AMD · January 1, 2006 This paper investigates methods of improving measurement interpretations in dynamic nanoindentation. In particular, a shift in the system's primary resonance is observed experimentally and investigated through modeling and numerical studies. The result of ... Full text Cite

Milling bifurcations from structural asymmetry and nonlinear regeneration

Journal Article Nonlinear Dynamics · December 1, 2005 This paper investigates multiple modeling choices for analyzing the rich and complex dynamics of high-speed milling processes. Various models are introduced to capture the effects of asymmetric structural modes and the influence of nonlinear regeneration i ... Full text Cite

A numerical study of uncertainty in stability and surface location in high-speed milling

Journal Article American Society of Mechanical Engineers, Manufacturing Engineering Division, MED · December 1, 2005 High-speed milling offers an efficient tool for developing cost effective manufacturing processes with acceptable dimensional accuracy. Realization of these benefits depends on an appropriate selection of preferred operating conditions. In a previous study ... Full text Cite

Nonlinear system identification of a MEMS dual-backplate capacitive microphone by harmonic balance method

Journal Article American Society of Mechanical Engineers, Applied Mechanics Division, AMD · December 1, 2005 This paper presents the nonlinear identification of system parameters for a capacitive dual-backplate MEMS microphone. First, the microphone is modeled by a single-degree-of-freedom (SDOF) second order differential equation with electrostatic and cubic mec ... Full text Cite

Experimental parameter identification of a time delayed system

Journal Article Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference - DETC2005 · December 1, 2005 This paper departs from the more traditional focus of systems with time delays - the loss of stability - to examine an intrinsic benefit of time-delayed systems and a novel approach for parametric identification. For instance, it is well-known that the pre ... Cite

Nonlinear behavior in dynamic nanoindentation

Journal Article Proceedings of the 20th Annual ASPE Meeting, ASPE 2005 · December 1, 2005 Numerical studies of Eq. (1), performed for several excitation voltage levels, show that the combination of transducer mechanical and electrostatic nonlinearity as well as the interaction force nonlinearity provide a significant source of error in dynamic ... Cite

Simultaneous stability and surface location error predictions in milling

Journal Article Journal of Manufacturing Science and Engineering · January 1, 2005 Optimizing the milling process requires a priori knowledge of many process variables. However, the ability to include both milling stability and accuracy information is limited because current methods do not provide simultaneous milling stability and accur ... Full text Cite

Nonlinear dynamics of high-speed milling - Analyses, numerics, and experiments

Journal Article Journal of Vibration and Acoustics · January 1, 2005 High-speed milling is often modeled as a kind of highly interrupted machining, when the ratio of time spent cutting to not cutting can be considered as a small parameter. In these cases, the classical regenerative vibration model, playing an essential role ... Full text Cite

Bifurcations of a planar pendulum driven at a tilted angle

Journal Article Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference - DETC2005 · January 1, 2005 This paper examines the bifurcation behavior of a planar pendulum subjected to high-frequency parametric excitation along a tilted angle. Analytical and numerical results show that small deviations from either a perfectly vertical or horizontal excitation ... Full text Cite

Analytical solutions to surface location error in milling

Journal Article Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference - DETC2005 · January 1, 2005 This paper provides two new analytical solutions to the computation of surface location errors, or part geometric errors that arise due to forced vibrations of the cutting tool, during stable milling. The two approaches are based on frequency domain and ha ... Full text Cite

Nonlinear identification of a capacitive dual-backplate MEMS microphone

Journal Article Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference - DETC2005 · January 1, 2005 This paper presents the nonlinear system identification of model parameters for a capacitive dual-backplate MEMS microphone. System parameters of the microphone are developed by lumped element modeling (LEM) and a governing nonlinear equation is thereafter ... Full text Cite

Fiber Bragg grating sensors for measurement of tool displacement

Journal Article American Society of Mechanical Engineers, Manufacturing Engineering Division, MED · December 1, 2004 This work introduces a novel method for measuring machine tool displacement using embedded fiber Bragg grating strain sensors. Fiber Bragg grating sensors have many advantages including greatly reduced size, immunity to electromagnetic interference, and hi ... Full text Cite

Influence of process dynamics on traditionally machined surfaces introduction

Journal Article American Society of Mechanical Engineers, Manufacturing Engineering Division, MED · December 1, 2004 Cite

Simultaneous optimization of removal rate and part accuracy in high-speed milling

Journal Article American Society of Mechanical Engineers, Manufacturing Engineering Division, MED · December 1, 2004 High-speed milling provides an efficient method for accurate discrete part fabrication. However, successful implementation requires the selection of appropriate operating parameters. Balancing the multiple process requirements, including high material remo ... Full text Cite

Limit cycles, bifurcations, and accuracy of the milling process

Journal Article Journal of Sound and Vibration · October 6, 2004 Time finite element analysis (TFEA) is used to determine the accuracy, stability, and limit cycle behavior of the milling process. Predictions are compared to traditional Euler simulation and experiments. The TFEA method forms an approximate solution by di ... Full text Cite

Multiple chatter frequencies in milling processes

Journal Article Journal of Sound and Vibration · April 24, 2003 Analytical and experimental identifications of the chatter frequencies in milling processes are presented. In the case of milling, there are several frequency sets arising from the vibration signals, as opposed to the single well-defined chatter frequency ... Full text Cite

Stability of interrupted cutting by temporal finite element analysis

Journal Article Journal of Manufacturing Science and Engineering · January 1, 2003 Chatter in milling and other interrupted cutting operations occurs at different combinations of speed and depth of cut from chatter in continuous cutting. Prediction of stability in interrupted cutting is complicated by two facts: (1) the equation of motio ... Full text Cite

Stability of up-milling and down-milling, Part 2: Experimental verification

Journal Article International Journal of Machine Tools and Manufacture · January 1, 2003 The stability of interrupted cutting in a single degree of freedom milling process was studied experimentally. An instrumented flexure was used to provide a flexible workpiece with a natural frequency comparable to the tooth pass frequency, mimicking high ... Full text Cite

Global attractors of high-speed milling - Analyses, numerics and experiments

Journal Article Proceedings of the ASME Design Engineering Technical Conference · January 1, 2003 High-speed milling is often modeled as a kind of highly interrupted machining, when the ratio of time spent cutting to not cutting can be considered as a small parameter, hi these cases, the classical regenerative vibration model, playing an essential role ... Full text Cite

Machining accuracy due to tool or workpiece vibrations

Journal Article American Society of Mechanical Engineers, Manufacturing Engineering Division, MED · January 1, 2003 This paper presents a newly developed method for predicting dimensional errors caused by vibrations of either the cutting tool or workpiece. In previous literature, this phenomenon has been described as the "surface location error" from process dynamics. A ... Full text Cite

Stability of up-milling and down-milling, Part 1: Alternative analytical methods

Journal Article International Journal of Machine Tools and Manufacture · January 1, 2003 The dynamic stability of the milling process is investigated through a single degree of freedom mechanical model. Two alternative analytical methods are introduced, both based on finite dimensional discrete map representations of the governing time periodi ... Full text Cite

Effects of radial immersion and cutting direction on chatter instability in end-milling

Journal Article ASME International Mechanical Engineering Congress and Exposition, Proceedings · January 1, 2002 Low radial immersion end-milling involves intermittent cutting. If the tool is flexible, its motion in both the x- and y-directions affects the chip load and cutting forces, leading to chatter instability under certain conditions. Interrupted cutting compl ... Full text Cite

Stability of interrupted cutting by temporal finite element analysis

Journal Article Proceedings of the ASME Design Engineering Technical Conference · January 1, 2001 Chatter in milling and other interrupted cutting operations occurs at different combinations of speed and depth of cut from chatter in continuous cutting. Prediction of stability in interrupted cutting is complicated by two facts: (1) the equation of motio ... Cite