Mechanical behaviour of bolted connection in bending evaluated with small-scale specimen

Abstract

A tensile experiment is usually adopted to evaluate the mechanical behaviour of bolted connections, such as slip, yield, and ultimate behaviours or resistances. Tensile force is given by a universal test machine. A small-scale specimen of a bolted connection with a few bolts in a half side is used for the experiment. The small-scale experiment gives the mechanical behaviours easily. Tensile force applies to the specimen in the experiment; however, the bolted connection in an actual structure is exposed not only to tensile force but also to shear force or bending moment. In this study, a small-scale bolted connection for a specimen was developed to evaluate the bending behaviour of the bolted connection. The bolted connection was cranked at the centre. The crank is intended to generate the bending moment by the eccentricity of the applying tensile force and the force axis line. The mechanical behaviour of the bolted connection was investigated by finite element analysis. The bending moment is obtained theoretically as a product of the force and the eccentricity. However, the analysis reduced the applied bending moment by 75% from the theoretical value. The cause of the reduction was the support condition at the ends of the bolted connection. In a theoretical pinned supported case, the applied moment was not reduced; on the other hand, in a clamped supported case, which was assumed clamping by chucks in a universal test machine, the applied moment was reduced. From this finding, the behaviour of bolted connection in bending would be obtained in a small-scale experiment; however, the specimen is needed to design considering the support condition at the ends of the specimen.