Stochastic fatigue crack growth simulation of interfacial crack in bi-layered FGMs using XIGA

Abstract

In this work, extended isogeometric analysis (XIGA) is employed to compute the fatigue life of interfacial edge cracked functionally graded materials (FGMs). The effect of multiple defects (holes, inclusions and minor cracks) on the fatigue life of the interfacial cracked FGM plate is evaluated by XIGA. The bottom layer of the bi-layered plate is made of aluminum alloy while the upper one is made of FGM. The gradation in FGM layer is taken from left to right with 100% aluminum alloy on left and 100% alumina (ceramic) on the right. The material properties in FGM layer vary exponentially from the left (alloy side) to the right (ceramic side). For stochastic fatigue crack growth modeling, the input parameters (fracture toughness, Paris constant, Paris exponent) are generated using a log-normal distribution. Paris law is used to evaluate the fatigue life of the interfacial cracked bi-layered problems. The effect of these input parameters is studied on the fatigue life in detail. The values of stress intensity factors are computed using domain based interaction integral approach. Several interfacial crack bi-layered FGM problems are solved and analyzed by the XIGA.