An optimized design of a connecting rod based on buckling and fatigue analysis

Abstract

Connecting rod, a vital component of an automotive engine, undergoes stress and deformation producing useful rotary motion. The following work was done aiming to fulfil a research gap in the premises of connecting rod. Even though quite a few numbers of works have been done to analyse Ti6Al4V as connecting rod material, none of them displayed a separate design based on its buckling load. However, calculating the design parameters and designing accordingly for different materials offers a chance of improvement. In this study, we designed a separate model for Ti6Al4V while maintaining same factor of safety against buckling which resulted in 60% weight reduction than the 42CrMO4 model. The design was verified using static and fatigue analysis in Ansys. The mass was even reduced further by response surface optimization technique weighing 0.196 kg only instead of original weight of 0.839 kg. This lightweight model made the design more compact and the reduced materials decreased engine load which improved the efficiency of the engine. Finally, how the neck radius affects the stress developed on the connecting rod was analysed and total deformation revealed a significant pattern with the increasing fillet radius and consequently the stress reduced drastically until a optimal point was reached. Finding this optimal fillet radius will help the future researchers to design more compact connecting rod with minimal stress and deformation