Investigation of stresses at a critical location for shape optimization of connecting rod using finite element analysis

Abstract

A connecting rod is an element that is used to transmit power from the piston to the crankshaft in an IC Engine. The behaviour of connecting rod is affected by the fatigue phenomenon because of its cyclic loading. Fatigue is the primary cause of catastrophic failure of a connecting rod in an IC Engine. In the present work, shape optimization of the connecting rod is carried out by finite element analysis under reversible cyclic loading. In every phase of reversible cyclic loading, the stresses are generated and the critical locations on the connecting rod are located. The modelling of the connecting rod is carried out on CATIA, and ANSYS workbench is used for the FEA. The effects of design parameters are investigated, such as of fillet radius, groove depth, and groove length, based on maximum stresses generated at their critical location. With an increase in fillet radius, and decreasing groove depth and length, the maximum stresses generated were reduced by 15.07%, 6.31%, and 7.55%, respectively, due to a decrease in stress concentration. Finally, the optimized model has reduced the maximum stress at the bigger end of the connecting rod by up to 26.44%. This connecting rod now has better longevity during the operation.

Keywords

• connecting rod
• shape optimization
• cyclic fatigue loading
• fem
• fea