Strain-rate-dependent model for the elastoplastic dynamic contact of sphere and plate

A force-indentation contact model is presented for the dynamic contact loading of elastoplastic particle and plate to incorporate the material's strain-rate-dependent plasticity, built theoretically from the well-known Hertz contact law and Hill's solution for elastic and elastoplastic quasi-static contacts. A theoretical relation of the relative impact velocity and plastic strain rate is introduced to solve the model's parameters. A Johnson–Cook strain rate dependence is included into the model to consider dynamic effects. We validate the model using finite element analysis and show that the model can accurately simulate the force-indentation relation. The impact responses of plate simulated by applying the model combined with a substructure technique are validated using finite element analysis and laboratory test. With the aid of the model, a significant decrease in contact pressure during fully plastic indentation and the independence of dynamic contact-loading path upon loading rate are observed. (paper)