Determination of the Elastic Constants of Composites Through the Inversion of Leaky Lamb Wave Data

Abstract

We describe an ultrasonic technique for the determination of the dynamic elastic moduli of fiber-reinforced composites through the analysis of guided wave speeds in laboratory specimens in the form of laminates. The wave speeds are measured by means of the leaky wave technique. A functional relationship, called the dispersion equation, Lamb (LLW) between the guided wave speed in the laminate, frequency and the dynamic elastic moduli of the material is derived through the use of a recently developed theoretical procedure. For a given set of data, the relationship is inverted by means of a systematic scheme to obtain the elastic constants of the material.