Semi-analytical method for accurate evaluation of axial stiffness of bolted member

A semi-analytical scheme combining finite element analysis (FEA) with analytical method is proposed to accurately evaluate axial stiffness of disc-shaped bolted members. An elaborated FEA model is adopted to obtain the member stiffness in each bolted joint with same material, and the influences of elastic modulus, Poisson's rate, total member thickness and assembly clearance on the member stiffness are investigated. Then the semi-analytical model is constructed to calculate the member stiffness in each bolted joint with same material. Meanwhile, the semi-apex angle of the compressive stress distribution in each member is calculated by using the equivalent bolted joint with different materials, hence the axial member stiffness in bolted joints with different geometry and material properties is accurately formulized. Compared with the FEA results, the relative error of member stiffness by the novel scheme gets within 3% and the absolute error reaches to 0.02 GN/m.