3H-2 Elastic Wave Propagation in Anisotropic Microstructures for the Interpretation of Laser Acoustic Measurements

The wave propagation in anisotropic 3D structures with arbitrary geometries is numerically calculated in order to interpret laser acoustic measurements in microstructures. The laser acoustic Pump-Probe technique generates bulk waves in structures in a thermo elastic way. Here, the wave propagation for various geometries and materials is investigated. In the first part, the wave propagation in isotropic, axisymmetric structures is simulated with a 2D finite difference formulation. The numerical results are verified with measurements of macroscopic specimens. In a second step, the simulations are extended to 3D structures with anisotropic material properties. The implemented code allows the calculation of the wave propagation for different orientations of the material axes (orientation of the orthotropic axes relative to the geometry of the structure). Limits of the presented algorithms are discussed and future directions of the on-going research project are presented