Research On Topology Structure And Robust Optimization Technology Of Thin-walled Plastic Parts

Plastics are the main non-metallic materials in automobile body and parts.Warpage deformation is the most common and the biggest quality problem in the process of forming plastic parts.With the development of injection moulding technology,the thinner and thinner wall thickness of plastic parts will become the trend.There are some problems in thin-walled injection moulding parts,such as poor rigidity and large warping deformation.Therefore,this paper introduces intelligent design and optimization theory and technology into the topological structure optimization and moulding process design of thin-walled plastic parts,and focuses on the following contents:(1)A multi-objective topology optimization strategy for thin-walled plastic parts is proposed.Considering the problems of poor rigidity and large warpage deformation of thin-walled plastic parts,the optimization objective is to reduce weight and minimize warpage deformation in turn,thus realizing the optimization of Parts' topological structure.(2)A Kriging model establishment and optimization method based on mutation particle swarm optimization is proposed.The Kriging proxy model between process parameters and warpage deformation is studied and established.Mold temperature,melt temperature,injection time,holding pressure and holding time were selected as process optimization parameters.Latin hypercube sampling design test and CAE simulation results were used as response values of training samples.The approximate function relationship between process parameters and warpage deformation values was established.(3)The process parameters optimization method based on mutation particle swarm optimization is proposed,and the process combination corresponding to the minimum warpage deformation is obtained.On the basis of deterministic optimization,a 6 Sigma robust optimization design scheme for injection moulding process is proposed.Monte Carlo simulation and mutation particle swarm optimization are used to realize the 6 Sigma optimal design,which makes the optimization solution far from the constraint boundary and improves the reliability and robustness.By using VB and MATLAB mixed programming,the above optimization algorithm is realized,and a set of application software including test design,agent model establishment,model accuracy test,process parameter optimization and quality prediction is compiled.The case analysis shows that the solution proposed in this paper is feasible and effective,and has guiding significance for actual production.