Structure Analysis And Lightweight Design Of Automobile Hub

With the continuous development of automobile manufacturing technology,the number of domestic cars has increased rapidly.Although the increase of car ownership means that people’s living standard has been improved,it also brings many environmental and energy problems.As an important part of automobile,the material consumption of manufacturing wheel hub is the minimum on the premise of meeting the basic requirements of vehicle for hub performance,which can not only reduce energy consumption and environmental pollution,but also significantly improve the vehicle handling performance.In this paper,the structure analysis and lightweight design of automobile hub are studied.Firstly,according to the provisions of GB/T3487-2005 for automobile rims and relevant industry standards,the physical model of 15 ×61/2J wheel hub is established by Solid Works.Through the topology optimization analysis of the straight spoke wheel hub model,the curved spoke wheel with cutting material which can not only bear large load but also meet the requirements of lightweight design is determined.Secondly,based on the fatigue cumulative damage theory,the fatigue life mathematical model of the wheel hub is established.By using the seamless integration of ANSYS Workbench and CAD modeling software,the finite element analysis of bending fatigue,radial fatigue and impact simulation test of automobile wheel hub is carried out,the final results show that the bending condition has the greatest influence on the spoke and the rim edge connected with it,the radial working condition has the greatest impact on the rim,and the impact condition has the greatest damage on the wheel rim and the location where the wheel spoke has been excavated.However,the stress values under the three working conditions are less than the yield strength of aluminum alloy material,which meets the requirements of normal working conditions.Again,through the constrained modal analysis and free modal analysis of the wheel hub with or without constraints,the modal frequency and modal shape diagram of the hub are obtained.Finally,the modal analysis results are analyzed and evaluated.The results show that the frequency values of road excitation,wheel imbalance excitation and drive shaft excitation are far less than those under free mode and constrained mode,which meet the design requirements.Then,according to the results of finite element static analysis and modal analysis,the aluminum alloy wheel hub was replaced by magnesium alloy and carbon fiber composite material,and its strength was checked.The results showed that the magnesium alloy wheel hub and carbon fiber wheel hub met the design requirements;the structure of aluminum alloy wheel hub was optimized.The thickness of rim,the thickness of spoke and the thickness of mounting plate were taken as the main design variables.The optimization results showed that the thickness of rim was reduced by 4.26%,the thickness of spoke was reduced by 30.08%,and the thickness of mounting plate was reduced by 24.67%.The results show that the stress and strain of the three kinds of hub are increased after optimization,but they still meet the design requirements.Finally,the weight of single aluminum alloy wheel hub is reduced by 2.13kg,magnesium alloy wheel is reduced by 1.31kg,and carbon fiber wheel is reduced by 1.26kg.Through the comparison of three kinds of wheel hub,it is found that aluminum alloy hub can better meet the requirements of lightweight and cost.Finally,based on the results of structural design and lightweight optimization of A356 aluminum alloy wheel hub,the process feasibility and accuracy of finite element simulation of the lightweight aluminum alloy wheel hub were further clarified through the casting simulation of lightweight aluminum alloy hub,which laid the foundation for the low-pressure casting molding of lightweight aluminum alloy hub.