Molding Optimization And Lightweight Of Injection Molded Structural Parts Based On Multi-scale Co-simulation Technology

With the development demand of global energy saving and emission reduction,as well as the gradual tightening of national environmental protection policy,the use of plastic instead of steel to achieve lightweight transportation has become one of the key development directions for manufacture industry.However,compared to traditional steel or alloy materials,plastic products are more susceptible to external conditions and other factors during the molding process,which makes it difficult to regulate the quality of plastic products.The use of software such as mold flow analysis can effectively reduce the threshold of regulation.The present research on plastic injection molded products mainly focuses on molding process simulation in mold flow software alone or mechanical property simulation in structural software,which ignores the influence of material changes during the molding process on the final mechanical properties of the product and makes it difficult to achieve the optimization.In order to improve the accuracy and effectiveness of the analysis results,this paper conducted a joint processstructure-optimization multi-scale simulation study based on Moldex3 D,Digimat and ABAQUS to investigate the influence of process parameters and gate position on the molding quality and mechanical properties of the products,so as to provide a theoretical basis and technical guidance for the molding optimization and lightweight design of injection molded structural parts.The main contents are as follows:(1)A theoretical model of multi-scale joint simulation analysis was constructed to realize the coupling analysis of mold flow and structure,and the feasibility of the multi-scale joint simulation method was verified.(2)The mechanical anisotropy of pure resin material injection molding at different gate positions was investigated.Secondly,a multi-scale joint simulation of the front bumper mounting bracket of polypropylene injection molding was conducted to investigate the effects of injection molding process parameters on the molding quality and macro mechanical properties of the mounting bracket.(3)Combined with the single-factor method and orthogonal experimental method,the effects of melt injection time,melt temperature,mold temperature and holding time injection molding process parameters on the warpage and microscopic fiber orientation and distribution in the fiber-reinforced PA66 products injection molded from automobile spare tire trays,as well as the effects of microscopic fiber orientation and distribution on the macroscopic mechanical properties of the molded products were investigated,and the optimization of the process parameters was completed.(4)The lightweight design and process molding optimization of the protective plate were completed by adjusting the wall thickness,reinforcement bars,gate position and process parameters.The results show that the maximum stress value of the optimized shield plate is reduced to 96.63 MPa,the maximum mechanical deformation is reduced to 2.13 mm,and the mass is 126.19 g,which is reduced 43.68 g.The weight reduction ratio is 25.71%.