Mixed mode stress intensity factors for deflected and inclined corner cracks in finite-thickness plates

Abstract

Mixed mode stress intensity factor solutions are presented for deflected and inclined corner cracks in finite-thickness plates under uniform tensile remote loading. Three-dimensional enriched finite elements, which contain analytically known crack tip displacement and strain fields, are employed in the analyses. The stress intensity factor solutions are generated for quarter-circular corner cracks with various deflection and inclination angles ranging from 0° to 75°. The effect of plate thickness on the mixed mode fracture solution is also investigated. In the analyses presented, crack length/plate thickness ( a/ t) ratio ranges from 0.2 to 0.8. It is shown that decreasing the plate thickness results in magnification of mixed mode stress intensity factors along the crack front. Crack propagation angles are also determined along the deflected and inclined corner crack fronts based on the computed mixed-mode stress intensity factor distributions. The solutions presented can be used to assess fail/safe conditions and fatigue crack growth for the three-dimensional cracks studied.