Boundary element method analysis on T-shape structure with crack

Abstract

When a structure is subjected to loading, stress will build up within the structure. The localized stress depends on the geometry of the structure. Computational method using boundary element method (BEM) was used to analyze the stress of a T-shape structure with a fillet subjected to biaxial loading. The T-shape structure is analyzed on plan stress condition. Stress analysis was carried out on T-shape structure without crack. In the region of high stress concentration, a crack slanted at 45 degree is on the T-shape structure. Localized constraint was imposed on the head and the shoulder of the T-shape structure. The constraint will cause a bending effect as an axial force is applied at the end of the shank. Computational result obtained are compared with similar analysis from finite element method (FEM). Result from cases that are without a crack show the highest stress concentration factor is found in the fillet region ranging from 0.6 to 4. Furthermore, as the head thickness, H, decreases the stress concentration factor increases. However, when the shank diameter, d, decreases the stress concentration factor decreases. In the presence of crack , the highest normalised stress intensity factor shift from the fillet region to the crack tip region. The same trends of the variation of normalised stress intensity factor was observed for a thick head, H, and a small shank diameter, d, will achieve a lower normalised stress intensity factor. Generally, the computational analysis agrees well with result from FEM analysis.