Stress and fracture analysis of short flat bars with projections using boundary element method

Abstract

Short flat bars with projections are widely used in many applications as a means of transmitting axial load between two components. With short flat bars with projections being ubiquitous across many sectors, it is of paramount importance that engineers design a safe bar to prevent accidents. However, often times, fatigue failure occur in them due to geometric discontinuities and cracks. In this report, the stress and fracture analysis of short flat bars with projections using Boundary Element Method (BEM) were conducted and examined. Varying geometrical parameters, boundary conditions and loading conditions were subjected on both short flat bars with projections without and with crack to understand their effects on the stress experienced by the short flat bar. Results obtained showed that high stress concentration was always located at geometric discontinuities, i.e., the fillet of short flat bars with projections. In addition, findings indicated that local constraints led to higher stress experienced by the component as compared to remote constraints. A decrease in fillet radius, a decrease in head length and an increase in head depth by and large also led to an increase in the stress concentration factor. Depending on the conditions, the relationship between these variables and the stress concentration factor may differ. On the other hand, an increase in head length, head depth and a decrease in fillet radius led to an increase in stress intensity factor. All in all, this project aims to provide a deeper understanding on the factors affecting the stress concentration in short flat bars with projections to enable engineers to enhance the safety and security of these bars.