New Design Approach to High-Strength Steel Staggered-Hole Bolted Connections Failing in Block Shear

Abstract

The complex behavior of high-strength steel staggered-hole bolted connections failing in block shear with a combination of tension and inclined shear behavior was studied in this work. In particular, the location of the fracture paths in the staggered zones correlated with the angle of the staggered holes instead of appearing on the centerline between the staggered holes. Furthermore, the nominal shear strength of the staggered-hole bolted connections in the staggered paths was affected by the combination of shear and tension rupture, accounting for two components, which were the shear strength on failure paths parallel to the force and the tension strength on the segments perpendicular to the force. Consequently, a design equation for block shear strength with staggered holes was proposed to account for the combined actions. It demonstrated better correlation with the experimental results than the predictions from current design standards. A total of 88 specimens with two G450 sheets with thicknesses of 1.9 and 2.4 mm were modeled by means of a finite-element model validated against the actual tests to achieve reliable data using a parametric procedure. In addition, four different types of configurations, including not only four holes but also three and five holes were modeled to investigate the effect of the inclined shear and tension zones on the block shear strength and behavior of the connections. The large data set was used for the verification procedure of the proposed formula.