Anisotropy of the Fracture of Single Crystal Silicon Studied by Nonlinear Surface Acoustic Waves

Due to the elastic nonlinearity of the material, high-amplitude surface acoustic waves (SAWs) undergo nonlinear sharpening during propagation, which may introduce damage or produce modification of material microstructure. For single crystal silicon, the nonlinear evolution of SAWs and the resulting dynamic fracture depend on the free-surface orientation and direction of propagation. To investigate the effect of the geometries on behavior of SAWs, we performed molecular dynamics simulations of the nonlinear evolution of SAWs on the single crystal silicon surface. The second-order nonlinear coefficient is used to quantify the degree of nonlinear evolution of SAWs. In addition, the critical strength of the {111} plane of silicon is evaluated based on the SAW nonlinear evolution method.