Optimization Design Of A RV Frame Based On Lightweight

Lightweight design of automobile is one of the most important measures to realize the purpose of saving energy,reducing emission,decreasing energy cost and achieving environmental protection.As the core component of the vehicle,the frame has a significant effect on the weight reduction of the vehicle.For the mini trailer-mounted RV,the lightweight design can be used to reduce the manufacturing cost for the enterprise,meet the weight requirements of the access,development and promotion of the RV market,increase the weight allowed for baggage,and finally help to enhance the market competitiveness of mini trailer-mounted RV.In this thesis,the body frame of a mini trailer-mounted RV was researched to achieve lightweight design.Firstly,a random road roughness model was established based on the harmonic superposition method.The dynamic model of the simple tractor and the trailer-mounted RV was built in ADAMS,a dynamic analysis software,to simulate the working condition at a constant speed on the random road when the RV was fully loaded.The dynamic peak force of the loads on the body frame was extracted from the dynamic analysis of the whole vehicle.Subsequently,the finite element model of the original frame was established,and the free modal analysis was carried out.At the same time,the vibration mode test of the frame was conducted.Comparing the results of the two analysis,the error was within a reasonable range and the validity of the finite element model and modeling method was verified.Based on the results of vehicle dynamic analysis,the finite element analyses of the frame on four typical load cases,bending,braking,turning and torsion were carried out.It was found that the material utilization rate of the frame was low and it was necessary to reduce the weight.Therefore,in HyperWorks,according to the exterior shape and space layout of the RV body,the overall body was optimized for single load case and multiple load cases with topology.Referring to the results,the frame structure was redesigned.Based on the design of experiments,the size optimization design of the beam sections with great influence on weight loss were selected and the final optimization scheme was obtained.Finally,the finite element analyses of the new frame structure under four load cases were carried out.Compared with the original frame,the performance was improved,with its weight reduced by 16.7kg and ratio was 14.7%.The weight reduction was obvious.The work in this thesis has a good application value for the trailer-mounted RV frame,and can provide reference for similar designs of related enterprises.