All-aluminum Body Frame Lightweight Design Of Pure Electric City Bus

With the rapid development of road construction in China,the usage of domestic city buses is increasing year by year.The lightweight design of city bus can improve the fuel economy and dynamic performance of city bus.The skeleton of city bus is the most important load-bearing structure,and the weight of the whole vehicle skeleton can account for 30% of the total weight of the whole vehicle.In order to effectively reduce the mass of pure electric city bus to enhance its endurance and meet the performance requirements of pure electric city bus,it is of great significance to design the all-aluminum body frame of pure electric city bus.This paper uses Hyperworks software to establish a finite element model of the all-steel body frame of a pure electric city bus,determines four typical working conditions,analyzes the stiffness,strength and modal characteristics of the all-steel body frame of a pure electric city bus,and verifies the accuracy of the model.Based on the finite element model of the all-steel body frame of the pure electric city bus,the upper frame material of the body is replaced from Q235 to aluminum alloy 6061,and the finite element model of the all-aluminum body frame of the pure electric city bus is established.The body frame does not meet the strength requirements.Therefore,the structural optimization of the key columns of the bottom frame and the upper frame of the car body is carried out,and the material in the insufficient strength area of the all aluminum body frame is replaced with aluminum alloy 6061T6,so that the all aluminum body frame of the pure electric city bus can meet the design requirements of stiffness and strength,and the weight is reduced by602 kg compared with the all steel body frame.In engineering practice,in view of the problem of complex structure,unsatisfactory material consistency,and high processing difficulty,the second solution is proposed,which is based on the all-steel body frame of the pure electric city bus,the body frame and the battery pack area frame material Replaced with aluminum alloy 6061T6,carried out static and dynamic analysis and size optimization design,so that the all-aluminum body frame of the pure electric city bus meets the design requirements of rigidity and strength,and the mass of the all-steel body frame is reduced by 740 kg.The results show that the all-aluminum body frame of the pure electric city bus designed in option 2 has higher strength and more obvious lightweight effect,which can provide a reference for the subsequent light-weight design of the all-aluminum body frame.