Application of a 3D constant-thickness element in thin-plate-soil dynamic contact interaction

To solve the dynamic contact problem between a thin plate and soil, a new 3D constant-thickness contact element based on the first-order numerical manifold method is proposed. In this method, the soil is modeled by a first-order basic function and the thin plate is modeled by a zero-order basic function. Using the principle of virtual displacement and a rigid-plastic constitutive model, the stiffness matrix of the new contact element was deduced. By adding a damping component and equivalent linear model, the second-order differential dynamic equation of the contact system was built. Then, the displacement and stress values of the dynamic contact process were solved using the four-order Runge-Kutta explicit method. Compared with the Goodman results, the new contact element agrees better with the experimental results when the thickness of the contact element is 0.06 times its width. Comparison with the field test shows that the new contact element is not only convenient for modeling but also has higher accuracy.