Stress Intensity Factors for a Functionally Graded Material Cylinder With an External Circumferential Crack

Abstract

This paper presents mode I stress intensity factors for external circumferentially cracked hollow cylinders, which are assumed to be made of functionally graded materials and subjected to remote uniform tension. The conventional finite element method is improved by introducing isoparametric transformation for simulating the gradient variations of material properties in the finite elements. This improved finite element method is verified to be effective and efficient. Various types of functionally graded materials and different gradient compositions for each type are investigated. The results show that the material property distribution has a quite considerable influence on the stress intensity factors.

An improved numerical method for computation of stress intensity factors along 3D curved non-planar cracks in FGMs

“…In the finite element formulation, material properties and their derivatives at integration points are computed using isoparametric interpolations (Li and Zou, 1998):…”

Determining the mixed mode stress intensity factors of surface cracks in functionally graded hollow cylinders

“…Notice that this subject has been already addressed in both past and present works. Specifically, previous works focused on the analysis of mode I SIF of circumferential cracks located at the outer [30] or the inner [31] wall of the cylinder; more recently, semi-elliptical circumferential surface cracks in hollow cylinders subjected to internal pressure have been also analyzed [32]; the crack opening displacements was employed to extract the mixed mode SIFs.…”