THERMOELASTIC WAVE PROPAGATION IN ANISOTROPIC LAYERED MEDIA - A SPECTRAL ELEMENT FORMULATION

The generalized dynamic theory of thermoelasticity is used to investigate the propagation of plane harmonic waves in anisotropic layered media using the Spectral Finite Element Method (SFEM). Two different theories, due to Lord and Shulman (LS model) and Green and Lindsay (GL model), are considered for spectral layer element (SLE) formulation. The element is formulated in the frequency domain and the exact solution of the transformed equation is used as the interpolating polynomial of the unknown variables, which are the mechanical displacements and the thermal field. Consequently, single element captures the essential wave response of a layer of arbitrary thickness, when subjected to high frequency impact loading. This element is used to study the characteristic of the thermal wave, also known as the second sound, using nominal computational resource. The study is directed towards finding the justification of using the non-classical model of thermoelasticity and the effect of different parameters on the overall thermal and mechanical field. Stress state within a layered media with general ply-stacking is studied and the limitation of the classical theory in stress prediction is shown. Thermal wave propagation due to temperature burst and heat flux is captured and their properties are discussed.