Numerical Simulation of Surface Acoustic Wave and Detection of Surface Crack in Steel

The surface acoustic wave (SAW) propagating in a sample of steel is simulated by using finite element method (FEM). The waves are excited by a load function with propagation properties such as phase velocity dispersion and wide bandwidth. A two-dimensional model consisting of surface defects loaded with a wideband 50–200 MHz and short time 0.1 μs displacement function is investigated in the time and frequency domains. By transient dynamic analysis, Fourier transform and dispersion calculation, snapshots of propagating wave and responses from sensing points are presented. It is indicated that this supervision approach is sensitive to the surface cracks and reflections.