Basic Connections
Lap Joints - Single Shear
The videos below shows how a lap joint acts in a situation of Single Shear. When the joint is pulled apart due to tensile forces acting on the primary member, the joint can fail in one of two ways. Either the bolts can shear in a single plane (indicated where they glow red during the animation) TOP VIDEO, or the plate material can pull through if the amount of steel between the bolts and the edge of the plates is insufficient to resist the tensile forces BOTTOM VIDEO. Resisting this sort of pull through shear will require that there is adequate thickness of plate material as well as distance from the edge of the plate. In a lap joint the line of the steel through the joint or splice ends up being offset by the thickness of the steel. In some applications this is not a problem. In others it might negatively affect the load path or the aesthetics of the connection.
LAP JOINT IN SINGLE SHEAR- SHEAR PLANE THROUGH THE BOLT SHOWN IN RED.
LAP JOINT IN SINGLE SHEAR - PLATE PULLOUT DUE TO TENSION SHOWN IN RED.