Inversion of composite material elastic constants from ultrasonic bulk wave phase velocity data using genetic algorithms

Abstract

In this paper, efforts on the reconstruction of material stiffness properties of unidirectional fiber-reinforced composites from obliquely incident ultrasonic bulk wave data, employing an inverse technique based on genetic algorithms, is described. Computer-generated ultrasonic phase velocity data, as a function of the angle of refraction in both symmetry and nonsymmetry through the thickness planes of unidirectional composites were used as the input to the genetic algorithm. A simple genetic algorithm, with optimal parameters chosen from the literature and numerical analysis (reported here), was implemented for the reconstruction. The inversion using this novel technique was found to be extremely promising in the characterization of the material stiffness properties. Stability to noise in the input phase velocity data set was also investigated. Advantages and disadvantages of the genetic reconstruction technique over conventional methods are also discussed.