Nonlinear elasticity in Abaqus for ultrasonic wave testing

Hi guys,

 I'm trying to model a metal plate with micro cracks in abaqus for ultrasonic testing and I want to look at the nonlinear responses of Lamb waves propagating in the material. As I'm new to Abaqus I'm not sure if this is feasible at all or not. I know people can set various nonlinear elastic or plastic properties for the material but in most cases the models are actually going through the simulated deformations. I guess it's kind of different for waves. So I'm just wondering if anyone happen to know how to model the inherent material nonlinearities that might generate higher harmonics propagating through the cracks.

 Thanks in advance!!