A Numerical Study on Computational Time Reversal for Structural Health Monitoring

Abstract

Structural health monitoring problems are studied numerically with the time reversal method (TR). The dynamic output of the structure is applied, time reversed, as an external loading and its propagation within the deformable medium is followed backwards in time. Unknown loading sources or damages can be discovered by means of this method, focused by the reversed signal. The method is theoretically justified by the time-reversibility of the wave equation. Damage identification problems relevant to structural health monitoring for truss and frame structures are studied here. Beam structures are used for the demonstration of the concept, by means of numerical experiments. The influence of the signal-to-noise ratio (SNR) on the results was investigated, since this quantity influences the applicability of the method in real-life cases. The method is promising, in view of the increasing availability of distributed intelligent sensors and actuators.

Locating Ships Using Time Reversal and Matrix Pencil Method by Their Underwater Acoustic Signals

“…TR calculates the position of a target in an inhomogeneous medium, using information from many sensors validating mathematical properties in the solution of the wave equation. The use of TR ranges from the location of electromagnetic phenomena, such as lighting discharges [8], to the monitoring of structural health problems [9], going by linear networks analysis [10] and in aperture radar imaging [11]. Specifically, on underwater acoustic applications, it is used in the detection of multidimensional signals in aquatic environments [12] and in processing information for UWA communication processes [13,14].…”