Research On The Damping Performance Of Rubber Floor Vibration Damping System Of EMU

The vibration damping system of the rubber floor of the EMU has the function of reducing vibration and noise,which can meet the needs of passengers on the safety,reliability and comfort of the vehicle system.Among them,the floor damper is an important component of the damping system,and its performance changing in the process of using will affect the entire system and the comfort of passengers.At present,only a few people are researching on it.The rubber floor vibration system has been used on the EMU for 5-10 years,but the changes of the damping properties is still unclear and it has affected the EMU maintenance and maintenance work.Therefore,the vibration damping performance of rubber floor damping system is studied in this paper.The main research contents are as follows:(1)The damping mechanism of EMU rubber floor vibration system is analyzed in this paper,and the mechanical model is established,the analysis indicated that the main influencing factors of the vibration damping system including dynamic stiffness,static stiffness,damping coefficient,temperature,time,vibration load and vibration frequency parameters,and the vibration transmission rate is used to measure the performance of vibration damping system.(2)The constraint mode and free model of rubber floor damper is analyzed by using ABAQUS software,and the analysis results shows that the natural frequency of floor damper avoids the 0-150 Hz effectively and its design is reasonable.The modal analysis and harmonic response analysis of the floor vibration system are researched through the equivalent plate theory,and the vibration acceleration response peak mainly concentrated in the 43 Hz,59Hz,74 Hz,88Hz and 149 Hz under the single point excitation.The efficiency of vibration damping system of the whole floor is about 80%.(3)The experimental studies on the change rules of damping vibration in the using process of the floor vibration system,the research results shows that the static stiffness,dynamic stiffness and damping coefficients increased gradually with aging process,but the loss factor had no obvious variation.In the using process of floor vibration system(5-150Hz),the system stiffness and damping coefficient increased with the using time increasing in the low and high frequency phase,but damping effect becomes worse because the effect of stiffness is dominant.Between low and high frequency,the damping increasing plays a leading role and the vibration damping effect becomes better.The damping effect of the high stiffness damper is better than the low stiffness rubber damper when the low frequency vibration is suppressed,and the damping effect of the low stiffness damper is better than the high stiffness rubber damper when the high frequency vibration is suppressed.(4)The neural network model is established by using BP neural network technology to predict the vibration transmissibility of the floor vibration reduction system,and the experiments data of the four stage repair and the five stage repair are used to test the data.The results show that the neural network model can be used to predict the damping performance of the floor vibration reduction system under the specific frequency and the prediction error is less than 10%,and the method can be used to help designers and maintenance personnel to understand the performance of the floor vibration damping system of EMU in the carriage.