Lightweight Design Of A Certain Recreational Vehicle Body Structure

The recreation vehicle is an important means of transportation for tourists to travel by car.Since recreation vehicle tourism mostly involves group trips to the outdoors,the safety performance and mileage of the recreation vehicle is quite important.The lightweight design of the recreation vehicle can effectively reduce fuel consumption and extend the cruising range.This paper used finite element analysis method for the body frame of a certain recreation vehicle,and carried out a lightweight design on the basis of not affecting the strength and rigidity of the vehicle.Firstly,a three-dimensional model of the recreation vehicle skeleton structure was established based on the drawings and measurement data,and the finite element model of the whole vehicle skeleton of the shell element was obtained through pre-processing such as middle plane extraction,mesh division and load determination.Secondly,By checking the strength and stiffness of the recreation vehicle under four common operating conditions.It was found that the bending stiffness of the car frame was slightly lower,and the strength met the requirements of use.The modal analysis and random vibration analysis of the whole vehicle frame were carried out.The modal frequency avoids the common excitation frequency from the road surface and the excitation frequency caused by engine idling,and has good dynamic performance.Combined with the spatial power spectral density of road roughness,the displacement response of the vehicle frame under the random excitation of the road surface was obtained.Thirdly,the buckling analysis of the electric push rod of the lifting mechanism that can lift the roof of this model of motorhome was carried out.A simplified buckling model of electric cylinder was established,statics analysis was carried out.The critical buckling load of the model was calculated,and the stability of this type of electric push rod under working condition was analyzed.Finally,the frame thickness was used as a design variable.The maximum stress and deformation under horizontal bending and emergency braking conditions were used as constraints,and the vehicle quality was used as the optimization target,and the response surface analysis method was used for optimization.Since the sensitivity analysis determines the design variables that were not sensitive to the performance of the body frame structure but were more sensitive to weight loss,the weight reduction effect was obvious,and the final vehicle quality was reduced by 6.4% compared with the original vehicle.The static and modal analysis of the optimized vehicle frame was performed again.The results show that the performance of the optimized vehicle frame structure meets the requirements.In this paper,the response surface optimization method is used to design the finite element model of the recreation vehicle,which provides a method to realize the large weight loss of the recreation vehicle.And it provides a theoretical basis for the improved design of the subsequent recreation vehicle.