A Study About Shape and Topology Optimizations on A Connecting Rod

Abstract

Internal combustion engines have progressed since they undertook a crucial role to convert chemical energy of fuel to mechanical energy with the reciprocat-ing motion of the piston. Structural elements performed a role under heavy con-ditions with their facing dynamic stresses especially on the connecting rod with compression and tensile stresses. To overcome these stresses, manufacturing methods and design of the connecting rod have studied by the engineers for the different size and types of the engines so far. Many software are interested in structural optimization due to the demand of the field and present means on the application of finite element methods. Instead of focusing on kinetics of the con-necting rod, this study, first, introduces design steps and optimization methods. Then, limitations were determined for a connecting rod, which had critical im-portance in a novel rhombic drive internal combustion engine (ICE). Shape and topology optimizations were used for the ICE part to reduce mass while keeping endurance limit of the structure. In the analyses, Hypermesh, Optistruct and Hy-perView tools of the HyperWorks were used. 50% mass reduction as a constraint was accomplished while the critical compression stress was increased only 26%, which was under the demanded limit of 320 MPa in topology optimization. In the shape optimization, maximum stress was increased to 304 MPa from 191 MPa while 20% mass reduction obtained. The results were compared with the former data.