Multi-objective optimisation of the engine connecting rod based on the response surface methodology

Aiming at the low efficiency and limitation of traditional methods in the optimisation design, an optimisation design method of the connecting rod is proposed. The static and dynamic are researched under typical working conditions. The five dimensional parameters of the connecting rod, namely, the small end depth, the shank depth, the arc length, the arc between the large end and shank, and the shank groove depth are chosen as design variables by using sensitivity analysis. The deformation, equivalent stress, and the natural frequencies are taken as target variables. Using Latin hypercube sampling, the sample points are obtained, and the mathematical model is fitted. The relationship is discussed through three-dimensional response surfaces. The solution is obtained by using a genetic algorithm. The results of optimisation show that without increasing the mass, the deformation, and equivalent stress decrease by 23.81% and 6.23%, respectively. In the meantime, the natural frequency increases by 6.79%, 3.14%, and 23.31%, respectively. Copyright © 2024 Inderscience Enterprises Ltd.