| It is a trend to reduce automobile fuel consumption and emissions by expanding the application range of plastic parts in automobiles.Glass fiber reinforced plastics are increasingly used in functional structural parts of automobiles because of their excellent mechanical properties,corrosion resistance and eas y forming characteristics.Because the mechanical properties of glass fiber reinforced materials are greatly affected by fiber arrangement,it is difficult to provide a very effective reference for the design of parts due to the results obtained by convent ional simulation methods for mechanical properties.This is an important factor limiting the wider use of glass fiber in automobiles.In view of the lack of precision in the current mechanical simulation of glass fiber reinforced plastic parts,this paper takes the front end module of glass fiber reinforced plastic of a certain model as the research object,and combines simulation analysis based on Moldflow and simulation analysis of mechanical properties based on Abaqus.The effect of glass fiber orientation and residual stress on the mechanical properties of the part is taken into consideration in the structural simulation to improve the stiffness simulation accuracy of the front-end module.And through comparing the experimental method and the conventional methods of differences in the simulation accuracy,the results show that the simulation method can effectively improve the front-end module of glass fiber reinforced plastic stiffness simulation accuracy,which can provide reference for further light-weighting of front-end module.The main contents of this paper are as follows:First of all,based on the isotropic material,the stiffness of the installation point of the front-end module is evaluated preliminarily.The topology optimization method for the installation points that do not meet the requirements is obtained.Secondly,the simulation analysis of the injection molding for the front end module is carried out to obtain the information of the fiber orientation and residual stress in the parts,and provide reference for the mold design of the parts.The optimized parts are modeled with Moldflow,and the effects of the use of sequential valve gate and non-sequential valve gate on the weld mark location,the average fiber orientation and the injection pressure are discussed,respectively.It is concluded that the gating scheme using sequential valve gate is better than that without sequential valve gate.At the same time,the cooling system is constructed by shortening the molding cycle.The analysis results show that the layout of the water route meets the requirements of product cooling and achieves the purpose of shortening the molding cycle.To optimize the warpage,the orthogonal experimental design method was used to optimize the mold temperature,melt temperature,pressure holding time,injection time and pressure protection pressure.The optimal process parameters were used to solve the model.The results showed that the average warpage of the optimized warpage decreased by 41.5% compared with the orthogonal experiment.Finally,the advanced material exchange module of Helius PFA was used to map the fiber orientation information,warpage information and residual strain information of the injection molding simulation to the structural mechanics simulation model,and the stiffness of the mounting point based on the anisotropic material front-end module was obtained.At the same time,the installation point stiffness experiment was carried out on the samples produced by gating system,cooling system and the best process parameter combination of sequential valve gate.By comparing the experimental results with the simulation results of isotropic materials and the simulation results of anisotropic materials,the stiffness simulation value of the anisotropic material based on the injection molding simulation is closer to the experimental value,which proves that the simulation method has a higher reference value. |
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