Computations of Stress Intensity Factors for Deep Cracks in Plates by Using the Tetrahedral Finite Element

Abstract

In this paper, stress intensity factor solutions for deep half-elliptical cracks that are applicable to the structural integrity evaluations of welded structures are presented. Welded structures generally have some weld residual stresses resulting in stress corrosion crackings (SCCs). This paper describes a simple way to compute the stress intensity factors under the weld-residual stresses and the mode I stress intensity factor solutions for deep half-elliptical cracks. The residual stresses are set to vary proportional to the constant, the linear, the quadratic and the cubic functions of x which is the distance from the plate surface. Although we use a straightforward finite element method to perform the computations, we can quickly generate the stress intensity factor solutions as we make use of automatic mesh generation program for the tetrahedral finite element. Thus, it is very tractable to generate the finite element models with cracks. Furthermore, present solutions can be compared with those of Li et al. which are also presented in PVP 2012. We conclude that present method is useful for the evaluations of SIFs of cracks under the residual stresses.