Numerical Analysis of Crack Growth in Composite Material Using Superposed FEM
Kazuhiro SUGA, Yuichi SHINTAKU, Shinji KOBAYASHI, Yoshitaka WADA and Masanori KIKUCHI
Abstract:The heterogeneous material properties affect on crack growth. For this reason, it is important to develop a simulation system to evaluate the crack growth in heterogeneous materials. This paper develops a fully automatic crack growth simulation system in heterogeneous materials based on Superposed FEM (S-FEM). The simulation should be treats mixed-mode loading condition. The virtual crack closure method (VCCM) is used for evaluation of the stress intensity factors (SIFs). The direction of crack growth is calculated by the maximum tangential stress (MTS) criterion, and the growth rate is calculated through Paris law. First, in order to demonstrate the effectiveness, the SIFs evaluated by the developed system are compared with those of reference solution, the boundary element method (BEM) and body force method (BFM). Then, two-dimensional crack growth problems are simulated using the developed system. The first example is crack growth in a plate with an interface between hard and soft materials. The crack tends to grow into soft material through the interface. The crack path and the change of SIFs are studied. The second example is crack growth in a plate with a slant phase interface. Simulated crack paths are compared with that of experimental paths. The well agreement of these crack paths shows the usefulness of the developed system for crack growth simulation in heterogeneous materials. Key Words:Superposed finite element method (S-FEM), Surface crack, Crack growth, Composite material, Interface, CFRP, Virtual crack closure-integral method (VCCM), Inner pressure