Three-dimensional quasi-static fatigue crack growth analysis in functionally graded materials (FGMs) using coupled FE-XEFG approach

Abstract

In the present technological scenario, functionally graded materials (FGMs) are being introduced by scientific community for a wide range of effective engineering applications especially in aerospace, nuclear reactor, bio-medical and military uses. Safety and long service life of engineering components made from FGMs are one of the major objectives of engineering design process. The prediction of fracture behaviour is quite essential for safe designing of such critical components. In this work, three dimensional quasi-static fatigue crack growth has been studied in FGMs. Effects of material gradient (due to FGMs nature) have been investigated in detail. Both crack growth contours and fatigue lives are studied with reference of material heterogeneity (FGMs). Detailed analyses are presented in the form of fracture toughness, crack growth contours and fatigue life cycles. Numerical results are presented for cyclic thermal and mechanical loading environments. The variation in the material properties for FGM has been modelled by exponential law. The solution methodology has been implemented in coupled finite element (FE) and extended element free Galerkin (XEFG) approach. Few planar and non-planar crack geometries are simulated to check robustness and accuracy of the proposed technique. It has been shown that employed computational approach provides accurate fracture studies and crack growth predictions for three-dimensional functionally graded materials.