Virtual Prototype And Multi-objective Lightweight Development For A Minibus Sliding Door

At present,the research of vehicle lightweight technology has become a hot spot in the vehicle field.Sliding door is a large-scale covers in automobile body and it has extremely important influence on the aesthetics,safety,and performance of the vehicle.Therefore,sliding door performance must meets design requirements when optimizing the weight of sliding door.This dissertation takes a minibus sliding door model of the enterprise as the research object,and carries out the research on layout and design of sliding door,virtual prototype analysis,finite element modeling and performance analysis and multi-objective lightweight optimization.The specific research content and achievements are as follows:(1)According to the shape of the entire vehicle,the A surface of the sliding door is determined.Based on the main section of sliding door,the layout of the sliding door guide,hinges,stoppers,door locks,inside and outside handles and reinforcements is completed.And then,the design of inner and outer plates,guide rails,hinges,stoppers,and sealing strips of sliding door are completed.Finally,analyze the kinematics performance of the sliding door by establishing the virtual prototype model of the sliding door,and the rationality of the sliding door layout design is verified.(2)The sliding door model is imported into the finite element software HyperMesh for geometry cleanup and meshing,and check the quality of mesh.Based on the actual working conditions,The finite element model of the sliding door mode,torsional stiffness,drooping stiffness,bending stiffness and concave resistance are constructed,and obtaining the simulation value of each performance,and compared them with the performance standards specified by the company.The results showed that the performance of the sliding door meets the design requirements,but there is a large space for optimization.(3)Based on the finite element analysis results of the sliding door,through the parameter study and sensitivity analysis,select 8 part thicknesses with large contribution as design variables.The sample points were designed by Optimal Latin Hypercube design method.The sample data were collected by the finite element software.Based onthe sample data and the Response Surface Methodology,creating approximate model of sliding door modal frequency,stiffness,concave resistance and mass.And verify the accuracy of the approximate model through the fitness map and accuracy parameters.The accuracy of the approximate model is verified based on the fitness map and the accuracy parameters.Finally,taking the maximum first-order modal frequency of the sliding door,the minimum deformation of the bending stiffness,and the minimum mass as objective.With the other performance standards defined by the enterprise as constraints,a multi-objective optimization model of the sliding door is constructed,then selecting the best solution from the Pareto non-inferior solution set.The optimized sliding door not only meets the design requirements,but also the weight loss ratio of the sliding door reaches 6.07%,the maximum deformation of the bending stiffness decreases by 9.03%,and the first-order modal frequency value increased by 4.08%.(4)Using the descriptive sampling technique in Monte Carlo Simulation,taking the multi-objective optimal solution of sliding door as an uncertain factor,analysis the robustness and reliability of the sliding door.And finally the Sigma quality level and reliability of the sliding door response functions are 8 Sigma and 1,so the optimized sliding door structure has good robustness.