Structural Analysis And Optimization Of The Bullet Train Air Conditioning Box

The air conditioning box,an important part of the air conditioning unit,is the main factor affecting the safety and stability of the moving vehicle.The inertial load and random vibration load caused by acceleration and braking during the operation process of the moving vehicle air conditioning box cause the failure of box structure easily,which affects the reliability and durability of air conditioning units seriously.Therefore,it is necessary to analyze the static strength and random vibration fatigue of the air conditioning box.With the high speed development of the EMU,lightweight design is needed to satisfy the higher quality requirement of the EMU.Therefore,the shape optimization of the bottom plate,cover plate and side board of the air conditioning box were carried out in this thesis.The content is organized as follows:Firstly,according to the structure principle of the air conditioning unit of the bullet train,the model of the air conditioning box is built up considering the simplification and grid division.Based on the static strength theory of structural analysis,static strength analysis is carried out to obtain the force and deformation of the structure under different load conditions.According to the analysis results,the air conditioning box meets the requirement of structure.Then,based on the theory of fatigue analysis,the fatigue strength of the air conditioner is calculated,and the modal analysis and random vibration analysis of the air conditioning box are performed to analyze the dynamic characteristics of the structure.Based on the theory of fatigue accumulation damage,the fatigue life of the air conditioning box structure is calculated.The results show that the structure of the air conditioning box meets the requirements of fatigue strength and fatigue life.Finally,according to the analysis results of static strength and random vibration fatigue of the air conditioning box,and in order to realize the light weight of the air conditioning box,and based on the topographic optimization theory,the shape and appearance optimization of the compressor bottom plate and the air conditioner cover plate of the air conditioning box are carried out,which will reduce the structural quality under the condition of ensuring its rigidity and strength.The design optimization scheme of the final air conditioning box structure is improved.According to the research results of the calibration of the structure of the air-conditioned box body after optimization,the optimized design scheme can guarantee the rigidity of the compressor floor and the air conditioning cover plate of the air conditioning box,and the stiffness of the side plate is basically unchanged.The quality of the air conditioning cabinet is reduced by 5.39%,and the optimization purpose is realized,it provides reference for the study of the structure optimization design of the air conditioning box in the future,and has certain practical application value.