Two contact models,the classical Coulomb contact model and the modified Coulomb contact model,are used in a fully coupled thermo-mechanical numerical model of friction stir welding, and the suitabilities of the two models to simulate the welding process are analyzed.

Based on the first-order shear deformation theory of the composite laminated plate,an FEA model and the method of free vibration analysis for the composite laminates with multiple through-width delaminations were developed,and a linearity contact model was established to simulate the interaction between upper and lower sub-laminates along the delaminated region during the vibration process.

Fractal surface was introduced into the average flow model and effect of elastic-plastic contact deformation of fractal surfaces on the flow factors and contact factor were analyzed based on the M-B fractal contact model for partial film lubrication.

Based on finite element method,a 3-D nonlinear analysis is made on the structure pattern of the inserted junction for the composite dam alternative to the dam of Guanyinyan Hydropower Station with simulation of the processes of both the construction and the impoundment of the rockfill dam by Duncan E-B model and interface model.

A new elasto-plasticity damage interface model called EPDI and its numerical method are presented to unitedly characterize the monotonic and cyclic behavior of interface between the structure and coarse grained soil.

The dynamic contact model of nonlinear seismic response of high arch dams with contraction joints;

Based on the theory of contact forces,3-D frictional contact non-linear dynamic contact model is put forward.

The piecewise linear contact force model of material layers during impact crushing is put forward, based on the quasi-static compression crushing experiments, in which the parameters of model are analyzed and a revert coefficient is introduced to express the relation between parameters.