Analysis Of Rigid-Flexible Coupling Vibration Of High-Speed Train Based On Model Reduction Theory

In recent years,with the design of high-speed trains,light-weight and heavy-duty lead to increasing vehicle vibration system many structure components vibration intensified.The problem of High-speed train large system coupling vibration is the current research hotspot.The method of modeling couping system and the efficiency of solving the coupling system are the key technologies.Therefore,how to establish accurate and effective coupling model is very important for high-speed train vibration analysis.The bogie frame plays an important role in the safe operation of high-speed trains as an important part of supporting the vehicle body and connecting the vehicle under the coupling system.The traditional modeling method regard bogie frame as a rigid body in the researching.Therefore it is necessary to consider the flexible characteristics of the bogie frame.However,the finite element model of the bogie frame is large scale and has a lot of degrees of freedom,which will lead to the low efficiency of the computer and the inaccurate of the calculation.In order to solve these problems,this paper uses the method of model reduction to reduce the degrees of freedom the finite element model of the framework,and then coupled the reduced frame model with other components to establish the rigid and flexible coupling model of the vehicle system and carryied out the vibration comparative analysis with Rigid body model of vehicle system.Specific research includes the following aspects:(1)Described the theory of model reduction and reduction methods,as well as the application areas.Based on the advantages and disadvantages of various reduction methods and the application areas,the reduction method of Guyan and IRS are chosed to reduce the finite element model of bogie frame.(2)The finite element model of the bogie frame is established,and the reduced model is obtained by using Guyan and IRS reduction technique to reduce the degree of freedom of the finite element model.The results show that the accuracy of the model is lower than that of Guyan by using the IRS reduction method,which can completely replace the original model for dynamic analysis by comparing the natural frequency and the modal shape of the reduction model and the prototype model.(3)The rigid body model of the vehicle system and the rigid and flexible coupling model of the vehicle system are established.The model of the fixed beam model is reduced by using the model reduction technique,and the accuracy of the model is verified.The rigid mass coupling model is established by the spring and the reduced beam,and the correctness of the rigid-flexible coupling model is verified.Based on the coupling idea of the reduced beam and the mass block,the rigid and flexible coupling model of the vehicle system including the flexible frame is established.(4)The modal analysis and vibration characteristics of the vehicle body rigid body model and the rigid and flexible coupling model of the vehicle system are completed.The random vibration analysis of the vehicle system is carried out by random vibration theory.Through comparative analysis,the results of the two models results showed that the elastic vibration of high frequency system in vehicle rigid flexible coupling model can reflect more flexible structure;In the low frequency flexible frame on the body and frame vertical,roll vibration is obvious,but on the body and frame of the lateral vibration has little effect on vibration;In the middle and high frequency of vehicle system was stronger than the system in low frequency vibration,which is consistent with the actual operating conditions of high-speed trains.