Unconventional block shear failures of bolted connections in cold-reduced steel sheets

This paper examines the block shear design equation proposed by the first author based on laboratory tests of bolted connection specimens failing in the conventional block shear failure mode. It shows that the explanation regarding the feasible mechanism of block shear failures previously provided by the first author does not necessarily apply to staggered bolted connections, in which the downstream bolts do not have the same edge distance. For staggered bolted connections, a block shear failure may occur through the shear rupture and tensile yielding mechanism for particular configurations, as demonstrated for the first time in this paper. The present laboratory tests included specimens failing in the split block shear failure mode. This paper presents the equations for determining staggered and split block shear capacities. It also cautions against potential misidentifications for the simultaneous shear and tensile ruptures mechanism.