Study On The Layout Design And Lightweight Design Of A Tail Gate

The tail gate is an extremely important opening and closing part of the automobile body system and its layout and design will directly affect the overall automobile beautiful,usability and safety,at the same time,it also involves environmental protection and energy saving,therefore the tail gate layout design and lightweight research is much necessary.This dissertation takes the tail gate of a mini-bus as the research object.Firstly,layout and design the tailgate structure.Secondly,carry out the performance analysis of tail gate.Finally,according to the analysis results,research the light weight of the tail gate.Specific research contents and results are as follows:(1)Layout and design of the tail gate: Firstly,determine the A surface modeling of the tail gate.Secondly,through the main section of the main part of the tail gate,complete the layout of the tailgate hinge,gas spring,limiter,rear wiper,tailgate lock and outer handle.Thirdly,finish the design of the inner and outer plates,the air spring,the rear wiper and the sealing strip.Finally,carry out the simulation analysis of the tail gate to check the rationality of the layout design of the tail gate.(2)The tail gate model which was designed was imported into finit e element analysis software HyperMesh to pre-treatment,and then the finite element model of the modal frequency,anti-concave,torsion,drooping,horizontal and bending stiffness of the tailgate was established.Finally its performance was analyzed and evaluated,compared with the enterprise standard,the results of performance meeting the design requirements.the modal frequency and bending stiffness being a bit close to the critical value,which need further optimization,and there is the lightweight space of the overall performance.(3)O n the basis of finite element analysis results of the tail gate and engineering experience,through the analysis of the sensitivity of the 11 parts thickness of the primary screening,selecting 6 parts thickness as the design variables.Then the optimal Latin square experiment design method is used to collect the sample points,and the response surface method is used to establish the mathematical model of the mass,modal frequency,stiffness and concavity,and the accuracy of the approximate model is tested.Finally,taking the minimum mass of the tail gate,the minimum displacement of the bending stiffness and the maximum modal frequency of the first order as the objective function,taking other performance requirements o f the tail gate for the enterprise as a constraint,using AMGA genetic algorithm,carry out the multi-objective optimization of tail gate.Obtain the Pareto non inferior solution of the tail gate mass and the first mode frequency and the displacement of the bending stiffness loading point and select the optimal solution to satisfy the conditions.(4)Taking the initial optimized design variables as the initial value of robustness optimization,jointing response surface approximation model,Monte Carlo simulation techniques,AMGA genetic algorithm with six sigma robustness optimization technology has carried on the robustness to the tail gate structure optimization.Eventually the first order modal frequency of the tail gate is increased from the initial value(30.67 Hz)to 34.756 Hz,avoiding the minimum limit of 30 Hz,which improved the tail gate modal performance robustness.Tail gate weight reduced 2.28 kg,reached 9.76%,and the reducing effect is very significant.Compared with initial multi-objective optimization scheme,the loading point displacement damping of bending stiffness of the tail gate is small and its quality level also did not change.However,the standard deviation is reduced from 0.197 to 0.087,which shows that the robustness has been greatly improved.