Determination of the Highest Potential Spots for Fatigue Failure in Parabolic Leaf Springs using the Maximum Variance Approach

Parabolic leaf springs have been used in suspensions of two-axle freight wagons. In real operating conditions, freight wagons are subjected to random loadings in longitudinal, lateral and transversal directions. Under these conditions, methods to treat random loadings should be used. Counting methods, such as the rainflow are very common in this type of analysis. In spite of its application, counting methods need too much computing resources, and because of that an alternative method based on the maximum variance (MVM) may be a more efficient method. An analysis based on finite element method together with MVM-based fatigue analysis is considered. The analysis was enriched considering the hardening cyclic model of 51CrV4 steel for the master leaf, the main component at which fatigue crack initiates. The MVM method allowed effectively determining different points with high potential for fatigue crack initiation for two different random loading scenarios, when they are compared to the typical fracture surfaces due to fatigue in different regions of the master leaf.