Genetic algorithm based reconstruction of the elastic moduli of orthotropic plates using anultrasonic guided wave single-transmitter-multiple-receiver SHM array

Abstract

The reconstruction of all nine unknown elastic moduli of orthotropic platestructures has been achieved using a single-transmitter-multiple-receiver(STMR) compact structural health monitoring (SHM) array. This methoduses the velocity measurement of the fundamental guided Lamb wave modes(S0 and A0), generated from a central transmitter, and received by a sparse array of receivers thatencircle the transmitter. The measured velocities are then used in an inversionalgorithm based on genetic algorithms. A prototype compact STMR array wasdeveloped and used in the measurement. Simulated data were used to demonstrate thefeasibility of the technique. Experiments were conducted on 3.15 mm graphite–epoxycomposite plate using a PZT based STMR array as well as laser vibrometer baseddisplacement measurement. Experimental Lamb wave velocity data were used tovalidate the present technique. This technique finds application in the areas ofmaterial characterization and SHM of anisotropic plate-like structures used inaerospace and automobile components made using fiber reinforced composites.