Vibration Analysis And Structure Optimization Of A Tractor’s Self-adjusting Steering Drive Axle

The self-adjusting steering drive axle of the tractor is the main load-bearing component of the tractor.Because its working environment is in harsh areas such as mountains and hills,the initial design of the drive axle often takes measures such as increasing the wall thickness to increase its strength and improve the tractor adapt ability.But this has also led to an increase in the weight of the tractor itself,which is not conducive to the operation of the tractor in the hilly area.Therefore,it is necessary to optimize the design to achieve the purpose of weight reduction.The self-adjusting steering drive axle is one of the important parts of the tractor,and the optimization design work on it can also provide a reference for the optimization design of the whole tractor in the future.In this paper,using Hyperworks finite element analysis software of Altair Company,the main body of the self-leveling steering drive axle housing and the drive axle housing composed of the main body of the axle housing and other parts are used to carry out relevant modal analysis and harmonious response analysis.The bridge vibration test and the main body hammer test of the axle housing verify the accuracy of the simulation analysis through the test.Finally,the topological optimization of the main body of the axle housing is carried out,and the main body of the axle housing is optimized according to the topological optimization results.The specific work is as follows:(1)Modal simulation analysis of the posture self-adjusting steering drive axle housing.First,simplify the three-dimensional model of the drive axle,and then import the simplified three-dimensional model into Hypermesh to divide the mesh,assign material properties and establish bolt connections,and obtain the finite element analysis model of the steering drive axle housing.The finite element model is constrained according to the real force of the posture self-adjusting steering drive axle,and the axle housing is subjected to a modal analysis with restrained states,and the first 6-order modal modes and natural frequencies of the steering drive axle housing are obtained.The modal analysis of the main body of the drive axle housing in the free state is carried out,and the modal mode and natural frequency of the main body of the axle housing in the frequency range of 0-4000 Hz are obtained.(2)The harmonic response simulation analysis of the drive axle housing is carried out,and the frequency-displacement curve,stress cloud diagram and energy cloud diagram of the drive axle housing in the Z direction are obtained.(3)The hammer test was carried out on the main body of the steering drive axle housing,and the resonance frequency data of the main body of the axle housing was obtained.Compared with the natural frequency data obtained by the free-mode simulation of the main body of the axle housing,it was found that the maximum difference between the two was only 9.42%.The accuracy of the finite element model is verified.(4)Carry out the vibration test on the steering drive axle,and obtain the time domain diagram of the vibration acceleration of the steering drive axle at the designated position under different gears and speeds.(5)Carry out topology optimization design for the main body of the drive axle housing,and use two topology optimization schemes with minimum flexibility and minimum volume as the optimization objectives,and obtain the material distribution cloud map under the two different schemes.Integrating the two material distribution cloud maps to optimize the design of the main body of the axle housing,the weight of the axle housing is finally reduced by 21.56%,and the optimized design effect is obvious.