An efficient method for nonlinear characteristic analysis of fixed contact surface and interface in bolted joint and its application

This paper proposes a modelling method for nonlinear characteristic analysis of bolted joint considering the combined effect of contact surface and the interface interaction. First, the discontinuous contact region of the bolted structure is regarded as a flat continuous medium based on the hypothesis of equivalent virtual material. Second, two user-defined elements are respectively developed to simulate the contact surface and flexible interface. Then, a typical example of bolted structure is simulated using the proposed method. The comparison of the simulation results and the measurements indicates that the method is valid for the nonlinear characteristic analysis of the joint. Moreover, the method also presents advantage in computational efficiency according to the comparison with the conventional FE model. Hence, the proposed method provides a feasible solution for bolted problem in practical engineering applications, such as the precision instrument design, ultra-precision position control and multi-body dynamics simulation of complex mechanical system.