A forward modeling method of assembly interface contact characteristics based on user-defined elements

The forward construction of the assembly interface model plays a fundamental role in the high-performance digital assembly model building. Aiming at the problem that it is difficult to accurately solve the interface thin-layer element parameters with dynamic inverse calculation method, a thin-layer element parameter modeling method based on multiscale morphology simulation is proposed. First, the user-defined elements (UEL) are developed, and its attribute parameters are continuously distributed in space. Then, the combination of macroscopic interface contact pressure and microscopic morphology realizes the efficient and accurate characterization of interface contact stiffness. On the macro scale, the pressure distribution characteristics of the assembly surface are extracted based on finite element theory. On the micro scale, the mapping relationship between the material properties of the thin-layer and the surface morphology is established based on fractal and Hertzian contact theory. Furthermore, the mapping relationship between the elastic modulus of the thin-layer element and the contact stiffness is established, which realizes the forward characterization of the interface contact characteristics. The equivalent model of the assembly interface is built according to the UEL and thin-layer theory. Finally, the dynamic experimental results are in good agreement with the simulation results, which verifies the effectiveness of the proposed modeling method. This study provides a basis for the forward modeling of assembly interface contact characteristics.