Multi-body Topology Optimization of Connecting Rod Using Equivalent Static Load Method

Abstract

AbstractTopology optimization technique is employed to optimize mechanical components of various mechanisms and internal combustion (IC) engines to improve the dynamic performance and minimize the overall weight of the system. Specifically, in IC engines, connecting rod is a critical component, which experiences high dynamic loadings with significant stresses. Connecting rod along with piston contributes much to exaggerating the unbalancing of the engine. Thus, weight reduction of a connecting rod is attempted in the present work, with a volume fraction value ranging from 0.3 to 0.9. The entire model of the IC engine is designed using SOLIDWORKS 2019 software and imported into Altair Inspire multi-body simulation software to analyze the motion study. Being operated in a dynamic situation, the boundary forces are considerably fluctuating. Thus, a static topology optimization process will not be sufficient as the optimal topology is a function of boundary force direction. Here, the boundary conditions of the connecting rod, such as forces and torques are analyzed using an equivalent static load method, which is used as dynamic load cases for topology optimization process. The topology optimization is conducted for the connecting rod at various volume fractions, maximizing the stiffness or minimization of compliance as the objective function. To obtain the better manufacturability of the topology, shape controls of the geometry are applied as symmetry and split draw. The obtained topology is analyzed to capture performance values such as maximum deflection values and Von-Mises stress. For volume fraction 0.7, the weight is reduced by 30%; the performance of deflection and Von-Mises stress are reduced by 11.09% and 14.42%, respectively.KeywordsComplianceConnecting rodDynamic loadingEquivalent static load methodInternal combustion engineTopology optimization