Simulation of Lamb Wave Excitation for Different Elas- Tic Properties and Acoustic Emission Source Geometries

In the present study the influence of microscopic elastic properties and the geometry of the acoustic emission (AE) source are investigated by finite element simulation. We investigate the formation process of Lamb waves in isotropic and anisotropic plate specimen by simulation of five different AE source configurations. As reference a microscopically and macroscopically homogeneous, isotropic aluminum specimen with point force couples is used. For fiberreinforced materials, the elastic properties are typically anisotropic. A comparison is made between the Lamb wave formation of the anisotropic, homogeneous model specimen and those of an anisotropic, microscopically inhomogeneous model. It is demonstrated, that the microscopic elastic properties of the AE source have significant influence on the excitation of distinct Lamb wave modes. This can be used to distinguish between failure mechanisms like fiber breakage or resin fracture in fiber reinforced materials.