Simulation of Nonlinear Rayleigh Waves Propagation in Cracked Layered Elastic Medium

The nonlinear Rayleigh waves in layered half space with micro-cracks are analyzed by using finite element method. The micro-cracks close or open under the traction of Rayleigh waves. This leads that the second harmonic of Rayleigh waves can be observed after interacting with micro-cracks. For micro-cracks near the surface of structures, the second harmonics can be obtained from Rayleigh waves modes passing through micro-cracks. However, for micro-cracks in the low-velocity interlayer, the second harmonics can be obtained only when the Rayleigh waves modes at low frequency interact with micro-cracks. Besides, the level of the nonlinear effect is influenced by the length and width of micro-cracks.