Structural Optimization And Fatigue Analysis Of Centerl Lifting Axle Housing Of Heavy Duty Truck

This topic originates form the new intermediate lifting axle housing product of Baotou BeiBen Axle Co.,Ltd. The main purpose is to research the product of which the static and dynamic analysis, according to the requeirments of the fatigue life, which making the optimized structure effectively, all of which be as the necessary reference data.In the study, mainly using ANSYS(APDL,Workbench) finite element software and ADAMS virtual prototype simulation software carry out the center lifting axle housing structure through static analysis, dynamic analysis, automatic dynamic analysis, structural optimization and fatigue analysis. The main research contents and the results are as follow:(1) The center lifting axle housing of the original structure dimesions is calculated which the static stress distribution and deformation through three typical operating conditions(①the maximum vertical force over the dynamic road;②the largest braking force on the emergency brake;③the maximum lateral force in the sideslip) by static analysis. Results suggest that condition①is the dangerous, the method of which the loads and constraints are used as the follow-up research.(2) Introduction of which the road roughness from the results that the dangerous conditions, after that vehicle is simulated by virtual prototype on four conditions(①40km/h on B road;②100km/h on B road;③40km/h on D road;④100km/h on D road) by automatic dynamic analysis to get the corresponding results of which the resonant frequency range is1～80Hz, which as the dynamic measurement odds of optimizing the structure.(3) The center lifting axle housing of which the original structure dimensions are analysised comprehensively on the dynamic characteristics. The results suggest that the second and third natural frequency of which the structure is in the resonant frequency range through modal analysis and that is much easier to be resonance on the low frequency. The results show that the proper increasement of the damping ratio can be reduce the impact load of the lifting axle structure effectively through harmonic analysis. The results of the transient analysis show that the structure stress of the center lifting axle of which the vehicle with a high speed in the D road is more heavier than others relatively.(4) Two dimensions structure are calculated on the two conditions (full load and overload load) by static structure optimization through ANSYS(Workbench), the results show that the structure stress of which the first scheme is more smaller than others. When the structure wall thickness is10.8mm, of which the quality reduces7.72%, the maximum equivalent stress reduces2.90%, the first natural frequency is90.67Hz (It is higher than the resonant frenquency range.), this structure is identified as the best optimization size.(5) According to the optimizated structure of which to be calculated by fatigue life analysis. Using the optimal scheme size of the center lifting axle structure which is fatique analysis and calculation on the four conditions of (2) respectively, the results show that the fatigue life of the structural is more longer and of which the safety coefficient is more higher on the condition①than others relatively, the fatigue data is most poorest on the condition④. Then, the vehicle is over the dynamic road at the low speed or lifting the axle should be promoted properly, to avoid fatigue failure of which because that the action of alternating stress, repeatly.