An Improved Stiffness Model for Bolted Joints

An improved stiffness model is proposed for bolted joints made of similar and dissimilar plates. A novel approach is used to obtain an expression for the effective area used for determining the joint stiffness. More accurate estimate of the joint stiffness provides a more reliable prediction of the joint behavior both during its initial assembly, as well as under subsequently applied tensile loads in service. The effect of the grip length-to-diameter ratio, joint sizes, underhead contact radii ratio, hole clearance, and plate material/thickness ratio are investigated. Experimental data are used for determining the envelope angle $α$ in the proposed analytical model. Finite element modeling is used for evaluating the accuracy of the proposed stiffness model.