Reliability-based high cycle fatigue design approach of parabolic leaf spring

Abstract

It is well established that the fatigue phenomenon of metallic structures such as leaf springs presents a random behavior, which is influenced by a probabilistic effect of many factors. This paper presents a probabilistic design approach to predict the high cycle fatigue behavior of a single asymmetric parabolic leaf spring. The suggested approach is used to assess the fatigue reliability of a single asymmetric parabolic leaf spring with uncertainties associated with its design parameters. This approach is based on the Gerber fatigue criterion, response surface method, and finite element model of the single asymmetric parabolic leaf spring. Two models of single asymmetric parabolic leaf spring are proposed: an analytical model based on the response surface method and a finite element one. To estimate the fatigue resistance according to the Gerber criterion, the probabilistic approach is developed using the “strength-load” method and the Monte Carlo simulation method. The dispersion of geometrical, applied loading, and material properties are taken into consideration. A comparison between fatigue reliability values, calculated by the application of Monte Carlo simulation method on the finite element and response surface models, indicates a good correlation between different method results.