Structural Optimization Design Of The Connecting Rod Based On Response Surface Method

The connecting rod is the main transmission mechanism of the internal combustion engine,and it is an important task to convert the internal combustion of gas into mechanical energy.During the operation of the engine,the connecting rod is subjected to complex alternating loads and the working conditions are very poor.With the promulgation of the CN6,the engine emissions and performance needs to be further improved,and the lightweight of each part is precisely the way to solve this problem.Under the design requirements of the strength and rigidity of the connecting rod structure,the weight of the connecting rod makes the working condition of the connecting rod even worse.Therefore,the finite element analysis and structural optimization of the connecting rod are very necessary.In this paper,the internal combustion engine connecting rod is taken as the research object,and the motion and force of the connecting rod are analyzed.Using the Pro/E parametric modeling function,a parametric model of the connecting rod is established.Through the finite element static analysis,the stress and displacement cloud diagrams of the connecting rod are obtained,and the dangerous areas of the connecting rod under different working conditions are analyzed.Through the analysis of the parameters of the connecting rod,the factors that need to be considered in the optimization of the connecting rod are determined.Based on the finite element analysis of the connecting rod,the sensitivity analysis of the nine design parameters of the connecting rod is carried out,and the influence degree of each parameter on the optimization process is obtained,and the four parameters with great influence are selected as design variables.The Kriging response surface model was constructed by obtaining 25 sets of sample points through the Optimal Space-Filling Design.The additional results of 10 sets of test points are used to verify the accuracy of the response surface model.It is verified that the constructed response surface model is reliable.Through the genetic algorithm,the response surface model of the connecting rod is optimized,and three sets of optimization design results are obtained.By comparing and analyzing,the optimal design parameters are selected.The design value is returned to the solution,and compared with the response surface prediction result,the mass error of the link optimization is less than 1%,the quality of the connecting rod is reduced by 13.07%,and the dangerous part of the optimized connecting rod model is analyzed,indicating the optimized connecting rod.Safe and reliable,complete the lightweight design of the connecting rod.