Design And Analysis Of Aluminum Alloy Body For Pure Electric Bus

In order to reduce pollution,protect environment and realize sustainable development,the pure electric vehicles as the main new energy vehicles has been a national strategic focus.Pure electric vehicles use motors instead of engines in traditional cars,and electric energy is used instead of fuel to provide the power source for automobiles.Due to the pure electric vehicle mileage,battery power will increase the weight of the vehicle.So it puts forward higher requirements for the lightweight of cars.Among them,the lightweight design of the body is one of the hot spots of the pure electric vehicle research.In order to solve “the last mile" of the residential area to the bus station,we realize the lightweight design of aluminum alloy body pure electric vehicle which according to the shuttle bus model.The topology optimization space is designed according to the basic demand parameters,such as body length and width and height,wheelbase,passenger number,location of doors and windows.The air conditioner is arranged at the front end of the body roof,and the battery is arranged under the body seat.The loads of the doors and windows and other parts are distributed in the body side.The loads of passengers and drivers are evenly distributed on the floor of the car body.Then,according to the characteristics of the bus in actual driving,the corresponding constraints are set up.In the finite element software Hyperworks,by using the topology optimization method,the best topology optimization structure is obtained with the optimization of the body structure flexibility and the volume fraction of not more than 0.2.Then,it is the design of body structure.In this paper,according to the results of topology optimization analysis,aluminum alloy profiles in engineering practice and connection technology,the distribution of body structure is designed in CATIA.At the same time,it also refers to the force transfer path and combined with the actual engineering material forming and connecting technology.Then,we should import the model into Hyperworks,decide finite element mesh,distribute the same load on the corresponding beam,set the same constraint,obtain the deformation and stress of the body structure under four typical conditions.The rationality of the structure is judged by comparing the analysis result with the allowable value of the material.In addition to the strength and stiffness,this paper also obtained the front six free mode.And the low frequency of the body should be in a certain range to avoid the risk of resonance.In order to ensure the strength of the aluminum alloy component joint does not decrease,the composite connection form is usually riveted or bolted or riveted with bolts。In this paper,the connection forms of aluminum alloy body members are mainly bolted connection and composite connection.In order to ensure the strength of the connecting parts of the body structure,this paper analyzes the local strength of the typical connection forms of the aluminum alloy body structure.The results show that the strength and safety factor of the connections in the connecting structure is greater than that of the whole body,so that the design of the aluminum alloy body meets all the strength requirements.