Contact pressure model of fastener interface with stress singularities

The contact problem of fastener interface is simplified an elastic punch frictionless contact subjected to normal force and bending moment. Based on BOGY's characteristic equation, the geometrical conditions of eliminating stress singularities near bi-materials interface end are investigated. An elastic punch frictionless contact model is proposed using GLADWELL's contact mechanics. The influence of bolt tension, assembly clearance and member materials on the contact pressure of fastener interface has been studied. The results show that under regulations bolt tension, assembly grade and member materials, the contact width doesn't fall into the class of receding contact, but the stress singularities has been obviously happen. The effects of bolt tension on stress singularities are negligible, while influence of the assembly grade and member materials is very markedly. The stress singularities of fastener interface inside are greater than one of outside as the elastic modulus of bolt material greater than the member. Otherwise, the inside stress singularities is less than outside one. Moreover, the comparison between the finite element analysis and the theoretical calculation results shows that the proposed model can accurately predict the contact pressure distribution of fastener interface.