3D modelling of fatigue crack growth and life predictions using ANSYS

Abstract

This study uses ANSYS mechanical APDL 19.2 to predict crack propagation trajectories and fatigue crack growth at constant amplitude loading. Mixed-mode fatigue life assessment is implemented by the Paris law model for different configuration of modified compact tension specimen (MCTS) in linear elastic fracture mechanics (LEFM). The methodology includes: evaluating stress intensity factors (SIFs), a direction of crack propagation and estimating fatigue life via incremental crack growth process. Predicted crack growth path in the present analysis revealed a change in orientation of the hole proportionately affected fatigue crack life cycles. The propagation of fatigue crack is mostly attracted to the hole and the crack could either curve its path and grow towards it, or bypass the hole and propagate. The mixed-mode fatigue crack path and fatigue crack growth from this study were validated by several crack growth experimental and numerical results in literature.

Keywords

• Fatigue life
• Crack propagation
• Mixed mode
• Holes
• ANSYS
• MCTS