Optimal Design Of Composite Stabilizer Bar Link

Reducing energy consumption and emission pollution has become an urgent task of the automotive industry.Lightweight is an effective means to achieve energy-saving and emissionreduction.Glass fiber reinforced plastic(GFRP)is an important lightweight material with the advantages of lightweight,high strength,high specific strength,high modulus and corrosion resistance.This paper takes the stabilizer bar link made of GFRP to be the study object,the process parameters of injection molding,numerical simulation of mechanical properties and optimization of structure parameters are studied.The main work is as follows:(1)Based on fluid mechanics and motion of fibers,MOLDFLOW software is used to simulate the filling,holding and warping process of link using RSC fiber orientation model.The effects of melt temperature,mold temperature,injection time,holding pressure and holding time on volume shrinkage ratio and warpage are analyzed by orthogonal test design.Based on technique for order preference by similarity to ideal solution(TOPSIS)method,multi-objective robust optimization of the three most influential process parameters is obtained,which makes both volume shrinkage ratio and warpage minimum and has strong anti-interference ability,and the robustness is verified by interference test.(2)Based on meso-mechanical homogenization method,considering the fiber delamination,the orthotropic elastic constants of GFRP are deduced according to the properties of matrix and fiber materials,mass fraction and fiber aspect ratio.The anisotropic material model is revised according to the tensile test results.Finally,the complete material model is obtained.According to the optimized injection parameters obtained above,the fiber orientation tensor under the optimized parameters is gained by MOLDFLOW analysis.The fiber orientation tensor is mapped to the structure analysis grids through grid nodes.The stiffness of the rod,the pull-out force of the ball-pin,the axial stiffness of the ball joint and the radial stiffness of the ball joint and are calculated by using anisotropic material model.The results are verified by tests on the stiffnesstesting machine.The relative errors between finite element calculation and test results are all less than 15%,which proves that the method is reliable.Compared with the results calculated without considering fibers,the errors between calculation and test results are larger,which further reflects the accuracy of the finite element calculation considering fiber orientation.(3)The pull-out force,the axial and radial stiffness of the ball-joint do not meet the needs made by an enterprise,so it is necessary to optimize the structure of the ball-joint.According to the stress nephograms results of finite element analysis,four structure parameters of stress concentration sites are selected.Considering the manufacturing feasibility of the structure,the ranges of variables are determined and the latin hypercube sampling method is used to arrange tests.The radial basis function proxy model of pull-out force,axial stiffness and radial stiffness on the four structure dimensions is established based on gauss function.The model has high accuracy and can take the place of finite element analysis.Sequential quadratic programming(SQP)algorithm is used to optimize the structure,and the performance of the optimized product design meets the requirements,the mass is reduced by 30%,and the lightweight effect is remarkable,the material substitution scheme is successful.The substitution scheme in this paper provides reference for material substitution of other automobile components.At the same time,the moldflow-structure finite element analysis method studied in this paper also provides theoretical support for the performance analysis and optimal design of plastics.