Numerical modeling of fatigue analysis of welded rectangular profiles under damped loads for automotive utilization

The welded structures are widely used in numerous industries, in particular, in automotive domain. Admittedly, they are subjected to repeated loadings, but, after a number of cycles, they fail due to a phenomenon called fatigue. The fatigue strength is commonly represented by the Wohler curve which is a plot of stress range against cycles to failure. Many parameters affect the fatigue of welded structures: The detail geometry, the stress concentration, the condition assumptions, the material properties, the welding process, the residual stress, and the environment. In this paper, a three-dimensional finite element method were built to calculate the stress and to evaluate the effect of the major factors that influence the fatigue strength on a structure based on welded rectangular profiles under damped loads. The results indicated the evolution of loading history as a function of available number of cycles. Also, we have demonstrated the influence of the spring stiffness on durability of our model; indeed, as the number of cycles increases the spring stiffness increases.