INFLUENCE OF THE STIFFNESS AND FRICTIONAL CHARACTERISTICS ON THE SHANK TORQUE OF SCREWS IN BOLTED JOINTS

This work aims at determining the influence of tribological and stiffness characteristics of a bolted joint on the residual shank torque of the screw. Even if it is commonly accepted to consider such a residual torque equal to half the torque at the thread, the literature lacks experimental data about the topic. The residual shank torque combines with the axial preload and the external loads to bring about the overall stress on the screw. Hence, the higher the residual torque, the lower the admissible external load for given size and class of the screw. From there stems the need for an analytical tool allowing the designer to calculate the residual torque as a function of the key parameters of the joint.