scholarly journals Decoupling Optimization Design of Under-Chassis Equipment Suspension System in High-Speed Trains

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Zhanghui Xia ◽  
Dao Gong ◽  
Jinsong Zhou ◽  
Wenjing Sun ◽  
Yu Sun
Keyword(s):  
Natural Frequency ◽  
High Speed ◽  
Optimization Design ◽  
Degrees Of Freedom ◽  
Vibration Mode ◽  
Ride Comfort ◽  
Vibration Damping ◽  
Dynamic Vibration Absorber ◽  
Damping Effect ◽  
High Speed Trains

The vibrations of high-speed trains may strongly affect the safety and ride comfort of passengers, which issue requires the damping optimization of under-chassis equipment (UCE). In this study, the natural frequency of UCE is determined via the dynamic vibration absorber theory. The performed investigation of UCE-car body system vibration behavior revealed that an eccentricity of UCE results in the coupling vibration in six degrees of freedom, which leads to significant changes in its vibration mode and frequency. Thus, the natural frequency of UCE deviates from the initially determined value, which implies that the vibration damping effect is weakened. In this study, two decoupling optimization design methods, namely, forward and inverse decoupling methods, are proposed to solve this problem. The analysis of results obtained proves the feasibility of the proposed methods, which yield favorable decoupling degrees for the UCE vibration modes and minimize the offset of the vibration mode frequency from the initial natural one. These methods are considered quite instrumental in the improvement of vibration damping effect for high-speed trains.

scholarly journals Study on Multi-Degree of Freedom Dynamic Vibration Absorber of the Carbody of High-Speed Trains

2021 ◽  
Author(s):  
Yu SUN ◽  
Jinsong Zhou ◽  
Dao Gong ◽  
Yuanjin Ji
Keyword(s):  
Vibration Control ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Dynamic Stiffness ◽  
Degree Of Freedom ◽  
Vibration Absorber ◽  
High Speed Train ◽  
Dynamic Vibration Absorber ◽  
Multiple Degrees Of Freedom ◽  
Dynamic Vibration

Abstract To absorb the vibration of the carbody of the high-speed train in multiple degrees of freedom, a multi-degree of freedom dynamic vibration absorber (MDOF DVA) is proposed. Installed under the carbody, the natural vibration frequency of the MDOF DVA from each DOF can be designed as a DVA for each single degree of freedom of the carbody. Hence, a 12-DOF model including the main vibration system and a MDOF DVA is established, and the principle of Multi-DOF dynamic vibration absorption is analyzed by combining the design method of single DVA and genetic algorithm. Based on a high-speed train dynamics model including an under-carbody MDOF DVA, the vibration control effect on each DOF of the MDOF DVA is analyzed by the virtual excitation method. Moreover, a high static and low dynamic stiffness (HSLDS) mount is proposed based on a cam–roller–spring mechanism for the installation of the MDOF DVA due to the requirement of the low vertical dynamic stiffness. From the dynamic simulation of a non-linear model in time-domain, the vibration control performance of the MDOF DVA installed with nonlinear HSLDS mount on the carbody is analyzed. The results show that the MDOF DVA can absorb the vibration of the carbody in multiple degrees of freedom effectively, and improve the running ride quality of the vehicle.

Nonlinear Vibration and Comfort Analysis of High-Speed Trains Moving Over Railway Bridges

Volume 2 ◽  
2004 ◽  
Author(s):  
M. H. Kargarnovin ◽  
D. Younesian ◽  
D. J. Thompson ◽  
C. J. C. Jones
Keyword(s):  
High Speed ◽  
Ride Comfort ◽  
Beam Theory ◽  
Maximum Acceleration ◽  
Railway Bridges ◽  
Comfort Index ◽  
Power Spectral ◽  
High Speed Trains ◽  
Train Speed ◽  
Track Bridge

The ride comfort of high-speed trains passing over railway bridges is studied in this paper. The effects of some nonlinear parameters in a carriage-track-bridge system are investigated such as the load-stiffening characteristics of the rail-pad and the ballast, rubber elements in the primary and secondary suspensions systems. The influence of the track irregularity and train speed on two comfort indicators, namely Sperling’s comfort index and the maximum acceleration level, are also studied. Timoshenko beam theory is used for modelling the rail and bridge and two layers of parallel damped springs in conjunction with a layer of mass are used to model the rail-pads, sleepers and ballast. A randomly irregular vertical track profile is modelled, characterised by a power spectral density (PSD). The ‘roughness’ is generated for three classes of tracks. Nonlinear Hertz theory is used for modelling the wheel-rail contact.

Dynamic Vibration Absorber for a Ropeway Carrier

1997 ◽  
Author(s):  
Hiroshi Matsuhisa ◽  
Osamu Nishihara
Keyword(s):  
Natural Frequency ◽  
Damping Ratio ◽  
Vibration Absorber ◽  
Moving Mass ◽  
Dynamic Vibration Absorber ◽  
Damping Effect ◽  
The World ◽  
Dynamic Absorber ◽  
First Time ◽  
Suspended Bridge

Abstract Ropeways such as gondola lifts have attracted increasing interest as a means of transportation in cities. However, swing of ropeway carriers is easily caused by wind, and usually a ropeway cannot operate if the wind velocity exceeds about 15m/s. The study of how to reduce the wind-induced swing of ropeway carriers has attracted many researchers. It had been said that it was impossible to reduce the vibration of pendulum type structures such as ropeway carriers by a dynamic absorber. But in 1993, Matsuhisa showed that the swing of carrier can be reduced by a dynamic absorber if it is located far above or below from the center of oscillation. Based on this finding, a dynamic absorber composed of a moving mass on an arc-shaped track was designed for practical use, and it was installed in chairlift-type carriers and gondola type carriers in snow skiing sites in Japan in 1995 for the first time in the world. It has been shown that a dynamic absorber with the weight of one tenth of the carrier can reduce the swing to half. The liquid dynamic absorber was also investigated. It has the same damping effect as the conventional solid absorber. It is easy to adjust the natural frequency and the damping ratio, and the structure is simple. Therefore, it will be applied for not only ropeway carriers but also ships and rope suspended bridge and others.

Evaluation of the Ride Comfort for High Speed Trains in Korea

2006 ◽  
pp. 1589-1592 ◽  
Author(s):  
Young Guk Kim ◽  
Seog Won Kim ◽  
Chan Kyoung Park ◽  
Kyoung Ho Moon ◽  
Tae Won Park
Keyword(s):  
High Speed ◽  
Ride Comfort ◽  
High Speed Trains

Optimization Design of DVG850 Worktable System Based on ANSYS Workbench

2012 ◽  
Vol 184-185 ◽  
pp. 356-359
Author(s):  
Jiang Miao Yi ◽  
Dong Qiang Gao ◽  
Fei Zhang ◽  
Huan Lin
Keyword(s):  
Modal Analysis ◽  
Natural Frequency ◽  
High Speed ◽  
Optimization Design ◽  
Element Model ◽  
Single Screw ◽  
Machining Center ◽  
The Finite Element Model ◽  
Better Than ◽  
Ansys Workbench

The finite element model of worktable system is created and modal analysis is made with ANSYS Workbench by taking DVG850 high-speed vertical machining center worktable system for example. We make modal analysis of single-screw strength general reinforcement worktable system and get the natural frequency and the vibration mode.Then in order to improve the system's natural frequency, the scheme of dual-screw worktable system is put forward. Also natural frequency and vibration mode is got. Finally, it is proved that the performance of dual-screw worktable system is significantly better than the single-screw one. This provides a reliable reference for further study on dynamic analysis of worktable system.

Structure Optimization Design of Drum of High-Speed Tire Test-Bed

2011 ◽  
Vol 291-294 ◽  
pp. 2306-2310
Author(s):  
Shi Wu Li ◽  
Jing Jing Tian ◽  
Zhi Fa Yang ◽  
Hai Zheng Wang ◽  
Lu Chen
Keyword(s):  
Natural Frequency ◽  
High Speed ◽  
Optimization Design ◽  
Operating Mode ◽  
Total Weight ◽  
Topological Optimization ◽  
Test Bed ◽  
Optimization Analysis ◽  
Element Density ◽  
Test Result

In order to study the effect of tire operating mode on its safety performance, a high-speed tire test-bed was put forward. The dynamic characteristic of drum was important for test result. To avoid the resonance of loaded drum during operation, the topological optimization analysis of drum with I-shaped structure was fulfilled with the element density as variables and the volume reduction of fifty percent as constraint condition and the first natural frequency as objective function. The optimal density distribution of drum was obtained within the constraint of the first natural frequency. Based on the analysis result of topology optimization, the drum structure with I–shaped was modified. The structure size of the new and improved drum was optimized with 50 iterative calculations using ANSYS. On the condition that the first natural frequency of drum was over 60Hz, the structure size of drum was optimal when the rate of the first natural frequency and total weight was highest and equaled to 0.05391. The optimization results showed the first natural frequency of drum was raised by 21.972Hz and its total weight was reduced by 69.95Kg.

scholarly journals Carbody vibrations of high-speed train caused by dynamic unbalance of underframe suspended equipment

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881896 ◽  
Author(s):  
Qunsheng Wang ◽  
Jing Zeng ◽  
Lai Wei ◽  
Bin Zhu
Keyword(s):  
Structural Damage ◽  
High Speed ◽  
Ride Comfort ◽  
Field Tests ◽  
Simulation Models ◽  
Mathematic Model ◽  
Dynamic Vibration Absorber ◽  
Elastic Suspension ◽  
Flexible Vibrations ◽  
Dynamic Unbalance

The effect of dynamic unbalance of the underframe suspended rotational equipment on the flexible vibrations of the carbody has become a major concern for high-speed trains. It is known from the field tests that the dynamic unbalance has a significant influence on carbody vibrations, especially the local flexible vibration, which leads to a decrease in the passenger ride comfort and may even cause structural damage to the carbody. A vertical mathematic model considering the carbody flexibility and the underframe suspended equipment is first set up, and then a three-dimensional dynamic model for a rigid–flexible coupled vehicle system is established. The effect mechanism of the dynamic unbalance on carbody flexible vibration is extensively studied, and the efficient measures to reduce the carbody flexible vibrations are proposed. The theoretical and simulation models are verified by comparing with a field test conducted on a newly designed high-speed railway. The results show that decreasing the unbalanced mass of the rotational equipment can reduce the carbody vibrations. Moreover, the use of elastic suspension for the underframe equipment can isolate the vibration transmission to the carbody. Both the theory of dynamic vibration absorber and dynamic unbalance should be considered to optimize reasonable suspension parameters, especially the suspension location and the suspension frequency.

Efficient evaluation of bridge deformation for running safety of railway vehicles using simplified models

2019 ◽  
Vol 23 (3) ◽  
pp. 454-467
Author(s):  
Zhibin Jin ◽  
Ligang Yuan ◽  
Shiling Pei
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Hertz Contact ◽  
Angular Rotation ◽  
Running Safety ◽  
High Speed Trains ◽  
Constraint Model ◽  
Response Errors ◽  
Large Wheel ◽  
Wheel Track

The running safety of high-speed trains over bridges is a great concern in bridge design. Typically, the running safety of vehicles is evaluated by vehicle–track simulations that are computationally expensive and unfamiliar to bridge designers. This study investigates simplified vehicle–track models for assessing the running safety of vehicles on deformed bridges. Four types of simplified vehicle models along with four types of simplified wheel–track models are investigated. The predicted wheel–rail forces are compared with those simulated by the detailed vehicle–track program. In these simulations, typical bridge deformations are taken as excitations to the dynamic system. It is found that omitting the rail vibration leads to large wheel–rail response errors. The wheel–rail constraint model gives similar wheel–rail responses to those obtained by the Hertz contact model. A vehicle–track model with five degrees-of-freedom is adequate for assessing wheel–rail forces. Furthermore, an analytical solution to the wheel–rail forces running over an angular rotation was obtained. These simplified vehicle–track models provide an efficient way to assess the running safety of vehicles on deformed bridges when using probabilistic or optimal analyses that require a large number of simulations.

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