Analysis and modeling for flexible joint interfaces under micro and macro scale

• A joint interface static/dynamic model combined micro and macro is established to analyze the structures with flexible joint interfaces.
• The surfaces with random topography are re-constructed by data point cloud.
• Contact analysis is conducted by FEM considering the elasto-plastic constitution of the material.
• The model involved micro and macro scale characteristics of the flexible joint interface has very high accuracy.

The flexible joint interfaces with random topography are re-constructed by data point cloud obtained by experimental measurements and a contact model between two rough random surfaces is established. Contact analysis is conducted by FEM considering the elasto-plastic constitution of the material. An exponential relationship model between normal pressure and normal deformation of the joint interfaces is presented by least-square method, and furthermore, the normal contact stiffness expressions of unit area of the joint interfaces are deduced. In order to use micro-scale model to deal with large scale practical engineering interfaces, a cantilever structure connected by bolted joint is taken as a macro scale example, and its dynamic model is established with the pressure distribution on the interface and real contact area obtained by simulations and experiments. Modal test experiments are conducted, and the first three natural frequencies and frequency response functions are obtained to validate the model.