Static And Dynamic Characteristics Analysis And Topology Optimization Of A Charger Box Structure

The charger of passenger train is a device which transforms DC600 V into DC110 V to supply for battery charging and lighting control. A large number of electrical equipment and electronic components are installed in the box. Considering the security and reliability of the maintenance system, the charger is actually the most important equipment in the power system. Once it breaks down, the battery will not work, so do all the devices which connect to the accumulator. Working as the structure foundation of the charger, the charger box hangs on the bus chassis beam through the hook. With the increase of speed, the longitudinal, transverse and vertical bearing in the operation of the train to the shock and vibration and other comprehensive load becomes more and more complex. The body and the mounting structure including operating vehicle hanger are turning worse. The strength and vibration characteristics of the box directly affect the normal work of electric components in the cabinet, even the safety of train operation. The structure analysis of box body is particularly important, and the results can provide further dynamic analysis and structure optimization design with the gist.Considering the structure, load and constraint conditions of the box, I make reasonable simulation scheme for the cabinet body and electronic components. The charger box and the electrical equipment are installed in the form of welding and bolt connection. I will apply the welding unit to simulate welding, apply the rigid element to simulate the bolt connection, apply the quality unit to simulate the electrical equipment cabinet, apply the Hyper mesh software to establish the finite element model of the box. I determine five kinds of ultimate loads, check the strength of the box in the force of inertia loads, do the static and modal analysis of box according to the standard of GB/T 21563- 2008. The analysis results show that the total deformation of the box is small, the structure stress is less than the yield strength of the material, the natural frequencies are higher than the excitation frequency of the bus body, and the resonance does not occur in the operation process. The box can meet the requirements of the train running condition. Finally, I do the design of topology optimization based on the results of the analysis of structural strength and get a box model redundancy. Under the premise of ensuring that the stiffness is basically equal to the strength and vibration performance, the charger body weight is reduced by 9.65%, and it meets the lightweight design requirements after optimization. Lightweight vehicle equipment not only can save materials and cost, but also comply with the development of the times. Furthermore, it’s of great significance to improve the performance of the train, reduce fuel consumption and exhaust pollution.