A detailed finite element analysis of composite bolted joint dynamics with multiscale modeling of contacts between rough surfaces

This paper presents the mull-scale modeling and finite element analysis of the dynamics of a composite structure with bolted joints. Microscale contact surface effects are considered and a single-degree-of-freedom (SDOF) stick-slip friction model is proposed. Interface mechanics parameters were solved using fractal contact theory and damping properties of the composite material were determined according to the elastic-viscoelastic correspondence principle. Then, by inputting calculated values for the penalty stiffness, damping coefficient, and material parameters, a finite element analysis of the overall and local dynamic response of the joint was carried out in ABAQUS. Simulated values of the resonance frequency and damping ratio of the structure were consistent with experimental results, thus validating the proposed model. Presence of the joint interface reduced the structural stiffness by 2% and increased energy dissipation by 30-40% compared to a rigid joint. Furthermore, the local interface energy dissipation was found to be influenced by both the excitation amplitude and preload. Finally, analysis of the interface roughness parameters showed that rougher surfaces facilitate preload relaxation.