Structural Performance Analysis And Optimization Of EMU Sanding Device

The technology of high speed railway has developed and improved continuously in recent years,the operation speed of EMU is constantly improving,and ensuring the safety of EMU in the process of operation is the prerequisite for the speed increasing.As an important structure component of EMU,sanding device can improve the adhesion coefficient between wheel and rail by sanding to ensure the smooth operation of EMU in harsh weather such as rain and snow,prevent wheelset idling and vehicle taxiing,and effectively avoid the occurrence of wheel rub fault.Therefore,to ensure the rationality of the design and the reliability of the sanding device is the key to the safe and high-speed operation of the EMU.In this paper,a certain type of EMU sanding device is taken as the research object.By using the FEA method,combined with the relevant theoretical knowledge of structural fatigue,structural reliability and structural optimization design,the structural performance analysis and reliability multi-objective optimization design of the sanding device are carried out to ensure that its structure meets the performance requirements and improves its structural reliability,thereby ensuring the safety of EMU operation.The main contents of this paper are as follows:Firstly,the structural performance of the sanding device was analyzed.According to the given three-dimensional geometric model of sanding device,the finite element model of sanding device is established by Hyper Mesh software.According to EN12663-2010 standard,the constraints and working conditions of the sanding device are determined and applied to the finite element model.Using ANSYS software is to analyze and check the static strength of the sanding device.On the premise that the static strength meets the requirements,the modal analysis is carried out to extract 1-10 order free modes and vibration modes of the sanding device.According to the vibration frequency,whether it meets the requirements of avoiding structural resonance is judged.The fatigue strength is calculated under the fatigue condition,and the fatigue evaluation position is determined by the calculation results and the corresponding principles.The fatigue evaluation of the sand spreading device is carried out based on the Goodman curve method and IIW standard.The results of evaluation show that the structure would not occur fatigue fracture,and the structure design is reasonable.Secondly,the structural reliability analysis of sanding device is carried out based on response surface method.The maximum stress condition is selected as the structural reliability analysis condition,and the limit state equation and structural reliability analysis model are established.The sensitivity of different structural parameters about stress is calculated,and several parameters with higher sensitivity are selected as input variables for reliability analysis.Using the Latin hypercube sampling design method to conduct the experimental design.The maximum stress of the sand dispersal device structure was taken as the output response.The response values of different input variables were calculated by finite element analysis.The least square method is used to fit the sample points to obtain the approximate function of the response surface of the stress and the input variables.Based on the response surface function,the structural reliability of the sanding device was calculated by Monte Carlo method.Using the above method to analyze the structural reliability,which fully considers the uncertainty in the design and manufacturing process of the sanding device.The calculation efficiency is high and the results are more convincing.Finally,the reliability multi-objective optimization of sanding device is carried out based on NSGA-Ⅱ algorithm.According to the results of sensitivity analysis,the corresponding plate thickness is selected as the design parameters,and the minimum structural weight and the minimum stress of the sanding device are taken as the optimization objectives.The structural reliability is greater than 91.88% and the range of design parameters are taken as the constraint conditions to establish a multi-objective optimization model.Combining with the double response surface function of structure weight and stress,the optimal design parameters combination is obtained based on NSGA-Ⅱ algorithm.The results of optimization show that the sanding device achieves the purpose of lightweight design with the improvement of structural reliability,and the multi-objective optimization results have more practical reference value.