Ultrasonic Wave Reflection From Liquid-Coupled Orthotropic Plates With Application to Fibrous Composites

Abstract

We present a unified analytical treatment supported by extensive experimental data of the interaction of ultrasonic waves with arbitrarily-oriented orthotropic elastic plates. The plates are assumed to be immersed in a fluid and subjected to incident acoustic beams at arbitrary polar and azimuthal angles. Reflection and transmission coefficients are derived from which all propagation characteristics are identified. Highly complex reflection behavior, expressed as phase velocity-frequency dispersion, is observed. Extensive experimental data has been collected in ultrasonic reflection measurements on a plate of T300/Ciba-Geigy 914 composite, selected as a model system to test the theory. Comparisons between theory and experiment show good agreement at several azimuthal angles between 0 deg and 90 deg.