Identification of Pre-Tightening Torque Dependent Parameters for Empirical Modeling of Bolted Joints

The vibration characteristics of bolted structures are crucially affected by the pre-tightening torque. An approach for identifying torque dependent stiffness parameters joints is proposed in this paper. Firstly, interface joint characterized thin layer element with isotropic material property, and parameter value property assigned relative to distance from center bolt; influence bolt ignored. Secondly, model updating method adopted identify elements using experimental data, modal data under different values range 2 N·m~22 N·m obtained; wrench used determine test. Finally, after partial on range, empirical equation obtained curve fitting rest verify accuracy fitted equations. It concluded that can obtain all equivalent within a certain torque, which provide reference modeling structures, improve efficiency reflect characteristic performance real structural dynamics.