On the estimation of material properties using guided wave measurements for the calibration of finite element models

The design and development of robust and reliable guided wave Structural Health Monitoring systems require accurate information of the structure’s material properties. This is needed by various analysis tools for the determination of wave propagation characteristics in order to evaluate and optimize the system’s performance. Estimation of the mechanical properties of composite materials using Lamb wave measurements is not straightforward as it requires the solution of an inverse problem. In this study, a numerical procedure is presented for the material properties estimation. The aim is to obtain estimates of the unknown material properties using circular surface mounted piezoelectric transducers that can be used for material characterization or calibration of numerical models. The procedure utilizes the Semi-analytical finite element method for the efficient computation of the dispersion curves and a genetic algorithm for the extraction of the material properties that fit best the experimental observations.