A limit analysis study to interpret the ultimatebehavior of bolted joints

The numerical study presented in this paper aims at assessing the role played by different aspects on the resistance of bolted joints in shear. To this purpose, a simplified procedure is proposed, based on rigid-plastic limit analysis, used in conjunction with a specifically devised finite element, essentially ‘‘plane’’ but accounting for the effects of transverse strain components. Results show that the model, although resting on drastic simplifying assumptions, permits a better understanding on the influence of a few important aspects affecting the overall joint behavior, such as the role of transverse plastic deformations, the restraining effect of the nut and the contact between the bolt and the metal plate. In particular, it explains how the nut and the washer have a fundamental role in bearing resistance of bolted connections and why pin design requires a different approach