Determination of the Strain Energy and Stress Intensity Factors with the Crack's Inclination under biaxial loading

Abstract

All components have certain flaws either interior or exterior on the surface which causes stress intensity under loading. The stress intensity exceeds the fracture toughness of the materials and causes failure of the component. A finite element analysis (FEA) was performed on Inconel 718 plate with a central crack under biaxial loading to compute the stress intensity factor (SIF) and the strain energy released rate (SERR) with the crack inclination ranging (ß) 0 °-150° and loading factor (B). The applied load is 10 MPa in the Y-direction (αy) while a range of -30 - +30 MPa in the X -direction (σx) with B of -3 to +3 was studied using COMSOL Multiphysics. The ratio of height to width of the plate is 1.25. The results show that the opening displacement was maximum at negative B (compression) while the minimum for positive B (tension) was at 90°. For mode I, the SIFs increase in compression and maximum at 90° while decreasing in tension and minimum at 90°. Beyond 90°, the SIFs increase under tensile while decreasing in compression load. For mode II, the SIFs were maximum at 45° for negative B while minimum at positive B.