Performance Analysis And Lightweight Design Of Drive Axle Housing Of High-power Wheeled Tractor

Drive axle housing as one of the main load-bearing components of high-power tractor,its reliability level is directly related to the reliability level of the whole vehicle,and based on the traditional experience design of the tractor drive axle housing is relatively conservative,the strength of the drive axle housing,stiffness appears excessive affluence,material redundancy,resulting in unnecessary waste.Based on this,this paper is based on a model of high-power tractor drive axle housing as the object of study,based on theoretical analysis,through the finite element method to analyze the static and dynamic characteristics of the drive axle housing.The performance parameters such as the inherent frequency of the drive axle housing and the strength,stiffness,fatigue life and safety coefficient under different working conditions are extracted and the performance parameter set is established.Based on the set of performance parameters,a combination of simulation and experiment is used to carry out the research on the lightweight design of tractor drive axle housing based on reliability.The specific research work of this paper is summarized as follows:(1)The finite element model of the drive axle housing was established,and the inherent characteristics of the drive axle housing,i.e.,the inherent frequencies and vibration patterns of the first six orders of modes,were obtained through the computational modal simulation solution.The modal test of the drive axle housing was carried out by building a modal test rig.The results of the computed modes were compared with the results of the test modes,and it was found that the vibration patterns were basically the same,and the maximum error in the values of the inherent frequencies of each order was 5.37%,which verified the correctness of the finite element model.And the influence of external excitation on the resonance phenomenon of the structure is analyzed.(2)The stress analysis and finite element simulation of the tractor drive axle casing under five typical working conditions were carried out,and the stress and displacement clouds of the drive axle casing and the maximum stress and displacement under each working condition were obtained.The fatigue life analysis of the drive axle casing under two working conditions was carried out at the same time.In working condition 1,the road load spectrum collected from the test was used as the input load by building the test platform of the whole tractor;in working condition 2,the equal amplitude sine wave pulsation cycle load spectrum based on the national standard was used as the input load.The minimum life cycle,the maximum damage value and the minimum safety factor of the drive axle housing under the two working conditions were obtained.The set of static and dynamic performance parameters of the drive axle housing is constructed.(3)The topological optimization design of the drive axle housing is combined with the set of performance parameters of the drive axle housing to propose a multi-objective dimensional optimization design scheme for optimally reducing the wall thickness of the main body of the drive axle housing.The thickness variables that can be optimized are screened by sensitivity analysis,and an RBF approximation model is constructed to express the relationship between the variables and the response.The results show that the 6σrobustness optimization method improves the reliability of the drive axle housing while ensuring the lightweight design,and the weight reduction is 10.1% compared with the original structure mass.The lightweighting effect evaluation coefficients were also constructed to evaluate the lightweighting effect.(4)The comprehensive performance test of the lightweight drive axle housing was carried out.The reliability of the lightweight drive axle housing was verified through the vertical bending stiffness test of the drive axle housing and compared with the simulation results,and the average error was 6.6%,which verified the correctness of the finite element simulation.And the drive axle noise and temperature performance test,noise measurement points are below 80 d B,temperature measurement points are below 45 ° C,the results show that all meet the design requirements.