Experimentally investigating finite element accuracy for ground vibrations induced by high-speed trains

2008 ◽  
Vol 30 (3) ◽  
pp. 733-746 ◽  
Author(s):  
Shen-Haw Ju ◽  
Hung-Ta Lin
2012 ◽  
Vol 226-228 ◽  
pp. 102-105
Author(s):  
Wen Qing Zhu ◽  
Yang Yong Zhu

With the rapid development of high-speed railway in China, the aerodynamic brake is very likely to be an important emergency braking mode of high-speed train in the future. This paper takes aerodynamic braking wing as the object, and uses the finite element software to divide the meshes, then analyses the model influenced by static stress. After simulating the vibratory frequency response of the model in the flow field, it finds that the largest deformation happens in the middle of the upper edge of the wind wing, when the wind speed gets to 500km/h and the load frequency to 4Hz. Some conclusions of this thesis can provide reference for researching the applying the aerodynamic brake in the high-speed trains and laying the foundation for solving the riding and braking safety problems.


Author(s):  
H-T Lin ◽  
S-H Ju

This paper investigates the dynamic characteristics of the three-dimensional vehicle-bridge system when two high-speed trains are crossing on a bridge. Multispan bridges with slender piers and simply supported beams were used in the dynamic finite element analysis. A response ratio (RR) was defined in this study to represent the ratio of the vehicle-bridge interaction of two-way trains to that of a one-way train. The finite element results indicate that this ratio increases significantly when two-way trains run near the same speed, and the maximum value is approximately equal to or smaller than two for the vertical dynamic response. This means that the maximum dynamic response of the two-way trains is at most twice that of the one-way train. When the two-way train speeds are sufficiently different, the response ratio approaches one on average, which means that the dynamic effect of the two-way train is similar to that of the one-way train. Finite element results also indicate that the averaged response ratio in the three global directions is about 1.65 when the two-way trains run at the same speed.


1997 ◽  
Vol 16 (4) ◽  
pp. 257-270 ◽  
Author(s):  
V.V. Krylov

Increase in speeds of modern railway trains is usually accompanied by higher levels of generated ground vibrations. In the author's earlier paper [V.V. Krylov, Applied Acoustics, 44, 149–164 (1995)], it has been shown that especially large increase in vibration level may occur if train speeds v exceed the velocity of Rayleigh surface waves in the ground cR., i.e., v > cR. Such a situation might arise, for example, with French TGV trains for which speeds over 515 km/h have been achieved. The present paper investigates the effect of geological layered structure of the ground on ground vibrations generated by high-speed trains. It is shown that, since Rayleigh wave velocities in layered ground are dispersive and normally increase at lower frequencies associated with deeper penetration of surface wave energy into the ground, the trans-Rayleigh condition v > cR may not hold at very low frequencies. This will cause a noticeable reduction in low-frequency components of generated ground vibration spectra. Theoretical results are illustrated by numerically calculated frequency spectra of ground vibrations generated by single axle loads travelling at different speeds and by TGV or Eurostar high-speed trains.


Author(s):  
BW Wu ◽  
QF Qiao ◽  
GX Chen ◽  
JZ Lv ◽  
Q Zhu ◽  
...  

This paper conducts a detailed investigation into the formation mechanism of wheel polygonalization in high-speed trains and its influence factors through numerical simulation. A finite element model including two rails, one wheelset, and three disc brake units is set up to study the formation mechanism of wheel polygonalization in high-speed trains based on the point of view of frictional self-excited vibration. Using the finite element complex analysis, the dynamic stability of the wheelset–track–disc brake system is studied. In addition, the influence factors on the wheel polygonalization are investigated. Results show that when the longitudinal creep force is unsaturated, the 21-order polygonal wear of wheels occurs easily due to the self-excited vibration of the disc brake unit. When the longitudinal creep force is saturated, the 12-order polygonal wear of wheels probably occurs due to the self-excited vibration of the disc brake unit. The bigger the friction coefficient between the brake disc and pad, the greater the occurrence propensity of the polygonal wear of wheels. Vertical fastener damping that is too large or too small is disadvantageous for suppressing wheel corrugation. However, increasing the lateral fastener damping is beneficial for reducing the polygonal wear of wheels. When the vertical fastener stiffness is 25 MN/m, 7-order, 9-order, and 14-order wheel polygonalization can easily occur. A higher lateral fastener stiffness is beneficial for the suppression of wheel polygonalization.


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