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Investigation of Broadband High-Frequency Stochastic Actuation for Active-Sensing SHM Under Varying Temperature



The main objective of this work is the investigation and numerical assessment of random (stochastic) broadband high-frequency actuation for active-sensing structural health monitoring (SHM) via stochastic time-series models, and the comparison with traditional deterministic tone-burst actuation under varying temperature. The main hypothesis examined in this work is that random broadband actuation, within the range of 100 KHz to 1MHz, may provide additional structural information due to the excitation of additional vibration modes compared to deterministic waves with the potential cost of requiring more elaborate signal processing, modeling, and diagnostic methods. Initially, a deterministic 5-peak tone burst signal is used to excite guided-wave propagation under varying temperature in an aluminum plate outfitted with piezoelectric disk transducers. Next, the same setup is used to induce broadband high-frequency random actuation in order to enable the stochastic modeling of the structure via AutoRegressive (AR) and Functionally Pooled (FP) models. The results of the study indicate the potential of using broadband high-frequency stochastic actuation for active-sensing SHM.


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