Member Stiffnesses of Axisymmetric Bolted Joints in Axial Tension

Reports of experimental and theoretical research have revealed that the conventional theory of bolted joints substantially overestimates the load factor and does not capture the joint non-linear behavior. Recently, a new analytical model of axisymmetric bolted joints in axial tension was presented, which, if all stiffnesses are obtained from finite element analysis (FEA), is able to replicate the FEA results. In this paper, based on FEA, formulas for calculating member stiffnesses of the new model of bolted joints are presented. Methods of presentation of stiffness formulas are investigated. Simplification of the new model is discussed. FEA examples are provided and compared with the predictions of the new model based on the presented formulas, simplified model, and conventional theory.