Numerical analysis on the ultimate bearing resistance of single-bolt connection with high strength steels

Abstract

This paper presents a numerical investigation on the bearing behavior of single-bolt connections with high strength steels in double shear. To simulate the phenomenon of accumulation damage shown in the post-peak behavior of bolt bearing and investigate the failure mechanism of tearout and splitting, the framework of ductile metal damage was used in the numerical model. The model was verified against the test results of bolted connections between high strength steel members. With the validated numerical model, a saddle-shaped distribution of the equivalent plastic strain was observed around the bolt hole, which explains the initiation and propagation of the fracture. A pure shear stress band, which is coincidence with the shear fracture in the experiments, was observed in the numerical analysis. In addition, the reduction of ultimate bearing resistance in splitting failure is explained by the increasing of lateral tensile stress at the tip of plate end with the decrease of edge distance. An extensive parametric study of 513 specimens was carried out to evaluate the effect of edge distance and end distance on ultimate bearing resistance. The boundary between tearout and splitting failure was established based on the distribution patterns of lateral tensile stress around the plate end. Finally, a new formula for predicting the ultimate bearing resistance with consideration of splitting failure was proposed.