Assessment of fracture reliability analysis of crack growth in spring clip type Vossloh SKL14

Abstract

Spring clips type Vossloh SKL14 (fastening system of track) are vulnerable to fatigue damage in lifetime due to excitations caused by traffic loads. This article has tried to develop a method for reliability analysis of spring clips type SKL14, based on fracture mechanics approach. First of all, a linear dynamic analysis of track has been done for dynamic response calculations under various traffic loads. The displacement time histories are applied on finite element method of type Vossloh SKL14 to achieve cyclic stresses. The equivalent stress range is described by lognormal distribution. Then, fracture reliability analysis has been done for crack propagation assessment in spring clip based on Paris’s law. This fatigue crack growth is dominated by a Mode I mechanism. A linear limit state function based on fracture mechanics is derived in terms of random variables. First-order reliability method has been employed for reliability estimation. At the end, the influence of various random variables on overall probability of failure has been studied through sensitivity analysis.