Fracture and Fatigue
This module dealt with structural failure mechanisms that occur over time or under critical loading — fracture mechanics and fatigue. Unlike simple strength calculations, these analyses focus on crack initiation, crack growth, and life prediction, which are central to durability in engineering design
The projects covered:
Fracture mechanics: simulating crack propagation using stress intensity factors (SIFs) and the JJJ-integral approach. I studied how different crack geometries and loading conditions influence crack-tip stresses and strain energy release rates.
Fatigue analysis: evaluating life prediction under cyclic loading using S–N curves and damage accumulation models. The homework emphasized how load spectrum, stress range, and mean stress corrections shape fatigue life predictions.
Mesh refinement strategies: applying local mesh refinement near crack tips to accurately capture singular stress fields without overburdening the rest of the model.
Comparisons with theory: validating numerical predictions against analytical fracture mechanics formulas to assess model reliability.
Working on these problems highlighted how sensitive fracture and fatigue simulations are to both geometry and loading assumptions. Small changes in crack length or local stresses can have an outsized effect on predicted life.
This module emphasized that safety in engineering is not just about withstanding today’s load but ensuring performance over thousands or millions of cycles. I learned how FEM extends into failure prediction, giving powerful tools for assessing durability, maintenance needs, and design safety margins