Contact characteristic parameters modeling for the assembled structure with bolted joints

Considering the non-uniformly distributed contact pressure, this study presents a new contact characteristic parameters (contact stiffness and damping) model for bolted joint interfaces. Firstly, to transform the contact pressure distribution into normal contact load distribution, the contact pressure distribution and its mathematical representation of single-bolted joint are studied. Subsequently, the relationships among contact stiffness distribution, contact damping distribution and normal contact load distribution are determined based on the improved MB model. It is found that the interfacial contact stiffness and damping exhibit significant inhomogeneous distributions. The proposed model overcomes the shortcomings of homogeneous distributions of contact stiffness and damping in bolted joints derived from previous models. In addition, the effects of bolt preload, tangential-to-normal contact load ratio and friction coefficient on the contact stiffness and damping are discussed in detail. Finally, the finite element (FE) analysis for beam lap structure with bolted joints incorporating the proposed model and the relevant experimental are performed to verify the validity of the modeling method. The results indicate that the proposed model can significantly improve the modeling accuracy of bolted joints.