scholarly journals Insights into the Effect of WJ-7 Fastener Rubber Pad to Vehicle-Rail-Viaduct Coupled Dynamics

2020 ◽  
Vol 10 (5) ◽  
pp. 1889 ◽  
Author(s):  
Linya Liu ◽  
Zhiyuan Zuo ◽  
Yunlai Zhou ◽  
Jialiang Qin
Keyword(s):  
High Temperature ◽  
High Speed ◽  
Coupling Model ◽  
Peak Frequency ◽  
Dominant Frequency ◽  
Dynamic Responses ◽  
Temperature Sensitive ◽  
Temperature Dependent ◽  
Vertical Coupling

The high-speed railway (HSR) has been a long-term hotspot in both scientific and engineering societies to enhance the long-term high quality HSR service. This study aims to investigate the WJ-7B type small resistance fastener rubber pad applied in HSR, and temperature sweep test is applied to determine the mechanical parameters of the fastener rubber pad, which are hereafter introduced into the vehicle-track-viaduct vertical coupling model via dynamic flexibility method. The track irregularity spectrum is considered as fixed-point excitation to investigate the temperature-dependent effect of fastener rubber pad on the dynamic responses. The results reveal that the rigidity of the fastener rubber pad is low temperature sensitive and high temperature stable, and the temperature variation has little effect on the vertical dynamic responses of the vehicle. The dynamic flexibility of the rail increases in amplitude and the dominant frequency decreases as the temperature of the fastener rubber pad increases. The vertical dynamic responses of the wheel-rail force, the wheelset and the rail-viaduct system gradually decrease as the temperature of the fastener rubber pad increases, and the peak frequency follows the similar rule. While under high temperature circumstances, the temperature dependent stiffness of the fastener rubber pad has little influence on the peak of the dominant frequency in the vertical dynamic response of the track-viaduct system.

Dynamic Responses Analysis of Vehicle and Track Based on Different Train Speed

2013 ◽  
Vol 706-708 ◽  
pp. 1314-1318
Author(s):  
Hong Mei Shi ◽  
Zu Jun Yu
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Coupling Model ◽  
Dynamic Responses ◽  
High Speed Railway ◽  
Vertical Coupling ◽  
Railway Infrastructure ◽  
Train Operation ◽  
Vibration Responses ◽  
Train Speed

With the rapid development of high-speed railway, dynamic interaction between vehicles and track is correspondingly strengthened. Therefore, dynamic responses analysis of the high-speed vehicles and track become more and more important to the train operation safety, riding comfort as well as the maintenance of railway infrastructure. In this paper, vehicle and track vibration equations are separately established based on the vehicle track vertical coupling model. Taking the CRH vehicle running on the existing line as an example, the random vibration responses of the vehicle and track under different running speed are analyzed in time domain through numerical integral method and MATLAB program. According to the results, the velocity of train has more influence on the vibration property of rail and wheelsets than bogie and carbody.

Estimation of Track Irregularity Based on Genetic Algorithm and Unscented Kalman Filtering

2012 ◽  
Author(s):  
Hongmei Shi ◽  
Zujun Yu
Keyword(s):  
Genetic Algorithm ◽  
Kalman Filtering ◽  
High Speed ◽  
Measurement Data ◽  
Estimation Method ◽  
Coupling Model ◽  
Dynamic Responses ◽  
The Real ◽  
True Value ◽  
Track Irregularity

Track irregularity is the main excitation source of wheel-track interaction. Due to the difference of speed, axle load and suspension parameters between track inspection train and the operating trains, the data acquired from the inspection car cannot completely reflect the real status of track irregularity when the operating trains go through the rail. In this paper, an estimation method of track irregularity is proposed using genetic algorithm and Unscented Kalman Filtering. Firstly, a vehicle-track vertical coupling model is established, in which the high-speed vehicle is assumed as a rigid body with two layers of spring and damping system and the track is viewed as an elastic system with three layers. Then, the static track irregularity is estimated by genetic algorithm using the vibration data of vehicle and dynamic track irregularity which are acquired from the inspection car. And the dynamic responses of vehicle and track can be solved if the static track irregularity is known. So combining with vehicle track coupling model of different operating train, the potential dynamic track irregularity is solved by simulation, which the operating train could goes through. To get a better estimation result, Unscented Kalman Filtering (UKF) algorithm is employed to optimize the dynamic responses of rail using measurement data of vehicle vibration. The simulation results show that the estimated static track irregularity and the vibration responses of vehicle track system can go well with the true value. It can be realized to estimate the real rail status when different trains go through the rail by this method.

scholarly journals Loss of DIAPH3, a Formin Family Protein, Leads to Cytokinetic Failure Only under High Temperature Conditions in Mouse FM3A Cells

2020 ◽  
Vol 21 (22) ◽  
pp. 8493
Author(s):  
Hiroki Kazama ◽  
Shu-ichiro Kashiwaba ◽  
Sayaka Ishii ◽  
Keiko Yoshida ◽  
Yuta Yatsuo ◽  
...  
Keyword(s):  
Cell Division ◽  
High Temperature ◽  
Temperature Sensitive ◽  
Dependent Manner ◽  
Temperature Dependent ◽  
Over Expression ◽  
Temperature Conditions ◽  
Family Protein ◽  
Temperature Environment ◽  
Ts Mutant

Cell division is essential for the maintenance of life and involves chromosome segregation and subsequent cytokinesis. The processes are tightly regulated at both the spatial and temporal level by various genes, and failures in this regulation are associated with oncogenesis. Here, we investigated the gene responsible for defects in cell division by using murine temperature-sensitive (ts) mutant strains, tsFT101 and tsFT50 cells. The ts mutants normally grow in a low temperature environment (32 °C) but fail to divide in a high temperature environment (39 °C). Exome sequencing and over-expression analyses identified Diaph3, a member of the formin family, as the cause of the temperature sensitivity observed in tsFT101 and tsFT50 cells. Interestingly, Diaph3 knockout cells showed abnormality in cytokinesis at 39 °C, and the phenotype was rescued by re-expression of Diaph3 WT, but not Diaph1 and Diaph2, other members of the formin family. Furthermore, Diaph3 knockout cells cultured at 39 °C showed a significant increase in the level of acetylated α-tubulin, an index of stabilized microtubules, and the level was reduced by Diaph3 expression. These results suggest that Diaph3 is required for cytokinesis only under high temperature conditions. Therefore, our study provides a new insight into the mechanisms by which regulatory factors of cell division function in a temperature-dependent manner.

The Design of New Type Muffler Used For Steam Turbine’s Exhaust Device

2010 ◽  
Vol 97-101 ◽  
pp. 4412-4414
Author(s):  
Jing Hong Yao
Keyword(s):  
High Temperature ◽  
Noise Reduction ◽  
Steam Turbine ◽  
High Speed ◽  
Steam Injection ◽  
Peak Frequency ◽  
Noise Attenuation ◽  
Sound Waves ◽  
Expansion Chamber ◽  
New Type

The exhaust device of steam turbine usually establishes vacuum rapidly using steam injection. The gas of the nozzle of the exhaust mixing device emits at high speed. The noise is very large. The muffler is designed to reduce the noise of the steam turbine’s exhaust devices. Referring to the principle of the separated expansion chamber muffler and connecting with practical production, we present a new type muffler. The design considers fully the peak frequency of the jetting noise of the nozzle and the noise attenuation of sound waves in the pipeline transmission etc. The muffler is small, light, anti- high- temperature and high-speed gases, and easy to be installed. The effect of noise reduction is obvious.

scholarly journals Study on the Urban Rail Transit Sleeper Spacing Considering Vehicle System

2019 ◽  
Vol 296 ◽  
pp. 01008
Author(s):  
Yu Zou ◽  
Yongpeng Wen ◽  
Qian Sun
Keyword(s):  
High Speed ◽  
Coupling Model ◽  
Vertical Vibration ◽  
Vibration Response ◽  
Urban Rail Transit ◽  
Vehicle Speed ◽  
Vertical Coupling ◽  
Vehicle System ◽  
Spectrum Density ◽  
The Impact

To design the optimal sleeper spacing of the track and reduce the vertical vibration of the rail, the influence of the sleeper spacing on the rail vibration is analysed in the vehicle-track vertical coupling model. By comparing the effects of vehicle speed and load on the vibration response of rails under different sleeper spacings, the importance of vehicle system is pointed out. According to the power spectrum density of the vertical rail displacement, the optimal sleeper spacing under the specific line is proposed, and verified via the vibration decay rate. The results show that the sleeper spacing directly affects the first-order Pinned-pinned vibration of the rail, and the effects of the speed and the load on the vibration response are different. In the low-speed section, the impact of the sleeper spacing on the vibration response is smaller, and the larger spacing can be appropriately selected to reduce the number of sleeper to save costs. However, in the high-speed section, the impact is larger, and the speed and the load should be comprehensively considered to select the optimal sleeper spacing.

Vibration Analysis of High-Speed Vehicles under the Condition of Track Random Irregularity

2011 ◽  
Vol 211-212 ◽  
pp. 525-529 ◽  
Author(s):  
Hong Mei Shi ◽  
Jia Liang Zhou
Keyword(s):  
Differential Equation ◽  
Numerical Simulation ◽  
Vibration Analysis ◽  
High Speed ◽  
Simulation Method ◽  
Coupling Model ◽  
Vertical Coupling ◽  
Vehicle Components ◽  
Track Irregularity ◽  
Random Irregularity

Track irregularity is the most important excitation source of wheel-rail system. The vibration characteristics of vehicle components and track components are analyzed in this paper under the condition of track irregularity by establishing the vehicle - track vertical coupling model. And the establishment of vibration differential equation and numerical simulation method for solving vibration response are described in detail. Finally, the results are given by MATLAB. The method is of great significance for evaluating the dynamic track irregularity and vehicle’s vibration at different running speeds.

Parameters Analysis of Train Running Performance on High-Speed Bridge during Earthquake

2010 ◽  
Vol 163-167 ◽  
pp. 4457-4463 ◽  
Author(s):  
Yu Sen Lin ◽  
Li Hua Xin ◽  
Min Xiang
Keyword(s):  
High Speed ◽  
Lateral Displacement ◽  
Damping Ratio ◽  
Dominant Frequency ◽  
Dynamic Responses ◽  
Natural Vibration Frequency ◽  
Wheel Load ◽  
Running Performance ◽  
Vehicle Acceleration ◽  
Train Speed

A model of coupled vehicle-bridge system excited by earthquake and irregular track is established for studying train running performance on high-speed bridge during earthquake, by the methods of bridge structure dynamics and vehicle dynamics. The results indicate that under Qian’an earthquake waves vehicle dynamical responses hardly vary with the increasing-height pier, but vehicle dynamical responses increase evidently while the height of pier is 18m, which the natural vibration frequency is approaching to dominant frequency of earthquake waves. Dynamic responses are linearly increasing with earthquake wave strength. Dynamic response of vehicles including lateral car body accelerations and every safety evaluation index all increase with train speed, so the influences of train speed must be taken into account in evaluating running safety of vehicles on bridge during earthquakes, but lateral displacement of bridge is varying irregularly. Dynamic responses and lateral displacement of bridge reduce under the higher dominant frequency of earthquake wave. Derailment coefficient, later wheel-rail force and lateral vehicle acceleration become small with increasing damping ratio. Vertical vehicle acceleration and reduction rate of wheel load are hardly varying with damping ratio.

Temperature-Dependent Small-Signal Analysis of High-Speed High-Temperature Stable 980-nm VCSELs

2009 ◽  
Vol 15 (3) ◽  
pp. 679-686 ◽  
Author(s):  
A. Mutig ◽  
G. Fiol ◽  
K. Potschke ◽  
P. Moser ◽  
D. Arsenijevic ◽  
...  
Keyword(s):  
High Temperature ◽  
Signal Analysis ◽  
High Speed ◽  
Small Signal ◽  
Temperature Dependent ◽  
Small Signal Analysis

Microstructural characterization of a rapidly solidified Al-Fe-V-Si alloy for elevated temperature applications

1988 ◽  
Vol 46 ◽  
pp. 550-551
Author(s):  
R. E. Franck ◽  
J. A. Hawk ◽  
G. J. Shiflet
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Grain Growth ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Temperature Applications

Rapid solidification processing (RSP) is one method of producing high strength aluminum alloys for elevated temperature applications. Allied-Signal, Inc. has produced an Al-12.4 Fe-1.2 V-2.3 Si (composition in wt pct) alloy which possesses good microstructural stability up to 425°C. This alloy contains a high volume fraction (37 v/o) of fine nearly spherical, α-Al12(Fe, V)3Si dispersoids. The improved elevated temperature strength and stability of this alloy is due to the slower dispersoid coarsening rate of the silicide particles. Additionally, the high v/o of second phase particles should inhibit recrystallization and grain growth, and thus reduce any loss in strength due to long term, high temperature annealing.The focus of this research is to investigate microstructural changes induced by long term, high temperature static annealing heat-treatments. Annealing treatments for up to 1000 hours were carried out on this alloy at 500°C, 550°C and 600°C. Particle coarsening and/or recrystallization and grain growth would be accelerated in these temperature regimes.

Sign in / Sign up

Export Citation Format

Share Document