High resolution operational modal analysis and virtual sensor expansion
This paper proposes a novel method to extract high resolution modes using output-only measurements from accelerometers or strain-gauges. A known GVT-calibrated finite element model is used together with sensor data to determine a dynamic model calibration and the associated loads. The Modal Frequency Decomposition and Reconstruction (MFDR) method can be used in support of Operational Modal Analysis (OMA) and allows the determination of dynamic signals in virtual sensor locations. Furthermore, the method allows the quantification of applied loads in form of residual loads. A verification case is presented with the numerical simulation of a rigid F/A-18 aircraft with elastic vertical tail, which is exposed to aerodynamic vortex buffeting. Four simulated accelerometer measurements are taken at the vertical tail and the modal analysis, as well as, applications of the virtual sensor expansion are shown. The presented work is part of a framework for Operational Analysis and Assets Diagnostics for individual aircraft tracking (OPERAND), a collaboration fostered between the Defence Science and Technology Group (DSTG) and RMIT University.
