Application Of Response Surface Methodology In Mechanical Structural Optimization

Response surface methodology(RSM)is a combination of mathematical and statistical methods,and plays an important role in the field of optimization design.Response Surface Methodology(RSM)can effectively reduce the number of experiments and solve optimization problems efficiently.In recent years,there have been many tentative explorations and applications in the field of mechanical structure optimization.In this paper,response surface methodology(RSM)is used to solve two kinds of typical optimization problems encountered in engineering cases.There are two typical optimization problems in engineering.The first is that there are many variables in the process of objective optimization,and some variables have little influence on the objective optimization.This kind of situation will increase the number of experiments in the optimization design and increase the workload.The second is that there is interaction between optimization objectives when multi-objective optimization is carried out.This kind of situation will have a great impact on the accuracy of the optimization target.In this paper,two typical optimization problems of coil spring torsional vibration damper and lifting arm are explored and solved based on the central composite design and Box-Behnken design of response surface method.In diesel engine,the torsional vibration of crankshaft will inevitably occur due to the fluctuation of engine torque.The coil spring damper is usually used to damp the torsional vibration of crankshaft.The mechanical properties and working reliability of the damper are important criteria for judging the excellent performance of the damper.In this paper,the mechanical model of the shock absorber is built,and the mechanical calculation is programmed.Compared with the repeated meshing required in finite element experiments,the computational program written in this paper can carry out experiments more efficiently and obtain the results.In this paper,nine variables in the damper are divided into four groups and three factors,and P value is obtained by variance analysis.Three experimental variables are selected as optimization factors.Based on response surface method,the damper effect of coil spring torsional vibration damper is experimentally designed with three factors in coil spring,and the damper effect of coil spring torsional vibration damper is optimized in the linear stage of pre-stress.That is,under the condition that the stiffness meets the design requirements,the strength of the reed can reach the desired goal.The efficiency of central composite design in structural optimization is embodied in response surface methodology.Because Box-Behnken method can accurately and effectively reflect the influence of optimization variables on the target response,this paper takes lightweight lifting arm structure and maximum stress of member as objective function.The crane arm model is drawn in CAD and the force analysis is carried out in ANSYS.In order to improve the efficiency of the experiment,the finite element simulation is mainly carried out in the form of command flow.A rectangular coordinate system is established,and the ordinates of six points on the left half of the structure of the crane arm are extracted as experimental factors.A response surface model based on Box-Behnken method is constructed for six variables.The lightweight structure and the maximum stress of the member are optimized by two objectives.Under the condition of fully considering the coupling relationship,the optimal results are obtained.It shows that the optimization based on Box-Behnken method is feasible when there is multi-objective interaction.In this paper,response surface methodology(RSM)is used to optimize the mechanical structures under two typical optimization conditions,which fully demonstrates that RSM,as a mathematical method,has high flexibility and can be used to analyze the typical optimal design in the mechanical field.Nowadays,with the rapid development of computer technology,response surface methodology(RSM)has been more and more integrated into all aspects of the mechanical field.Whether through the preparation of simple calculation program or the simulation of finite element software,it brings a lot of convenience to the optimization experiment in response surface,and also makes RSM more and more appear in the mechanical field.