Vibration Issue and Its Optimization of the Floor Structure in Electric Multiple Unit Trains

Abstract:

For the problem of the vibration on the floor structure in an electric multiple unit (EMU) train when running at a high speed, insitu tests are carried out. Vibration transmission analysis and ride comfort analysis show that the vibration transfers from the steel structure to the floor structure is amplified in the frequency range from 20 Hz to 50 Hz, which is the sensitive frequency range that covers the human legs. To study the floor vibration amplification mechanism, a finite element model of the railway vehicle car body which includes the floor structure is established and verified. The results of the finite element analysis show that due to the improper stiffness of the original elastic support components, the frequencies of the eigenmodes of the floor structure close to those of the steel structure, which leads to the resonance phenomenon between them, then the floor vibration energy is enlarged. Finally, the optimization of the elastic support stiffness parameters is studied and verified by the test. The test results show that the optimized design effectively solves the vibration problem of the floor structure.

Key words:electric multiple unit trains; floor structure; elastic support component; modal parameter