Multi-Axial Fatigue of Sheet Metal Joints Under Clamp Load and Cyclic Bending Available to Purchase

A validated Von-Mises stress-based model is presented for multi-axial fatigue evaluation of clamped sheet metal joints that are subjected to a cyclic bending stress additional to the compressive bearing stress in the bolted joint. Joint material, bolt preload level, and the amplitude level of the cyclic bending moment are studied for their effect on the fatigue life of the clamped sheet metal plate. Bolt tightening to a precise preload level is accomplished by using an ultrasonic instrument that has been mechanically pre-calibrated to convert the time delay of longitudinal ultrasonic wave reflection to a bolt elongation and corresponding preload value. Fatigue data is generated using an MTS fatigue testing system. Experimental and FEA results are fitted into a multi-axial model for predicting the fatigue behavior of the bolted joint. Discussion and data analysis are provided.