scholarly journals Modelling and Experimental Validation of the Dynamic Damping Characteristics of A High-speed Train Hydraulic Damper

2021 ◽  
Vol 1877 (1) ◽  
pp. 012028
Author(s):  
Youquan Fan ◽  
Shan Zhu ◽  
Yongming Wu ◽  
Wenlin Wang
Keyword(s):  
High Speed ◽  
Experimental Validation ◽  
High Speed Train ◽  
Hydraulic Damper ◽  
Damping Characteristics ◽  
Dynamic Damping

Prediction of the in-service performance of a railway hydraulic damper

2016 ◽  
Vol 231 (1) ◽  
pp. 19-32
Author(s):  
Wenlin Wang ◽  
Dingsong Yu ◽  
Rui Xu
Keyword(s):  
High Speed ◽  
Influential Factors ◽  
Service Performance ◽  
Relief Valve ◽  
High Speed Rail ◽  
Hydraulic Damper ◽  
Damping Characteristics ◽  
Model And Simulation ◽  
Wide Range ◽  
Entrained Air

In this study, an improved physical parametric model with key in-service parameters was established and experimentally validated for a high-speed railway hydraulic damper. A subtle variable oil property model was built and coupled into the full model to address the dynamic flow losses and the relief-valve system dynamics. Experiments were conducted to evaluate the accuracy and robustness of the full damper model and simulation, which determined the damping characteristics over an extremely wide range of excitation speeds. Further simulations with in-service conditions and excitations were performed using the validated model, and the results revealed that improper key in-service parameters, such as improper rubber attachment stiffness, entrained air ratios and small mounting clearances, can greatly degrade the damping capability of a hydraulic damper. The obtained physical model includes all the influential factors that have an impact on the damping characteristics, so it will serve as a useful basic theory in the prediction of in-service performance, optimal specification and product design optimization of hydraulic dampers for modern high-speed rail vehicles.

Multi-objective design optimization of the complete valve system in an adjustable linear hydraulic damper

2010 ◽  
Vol 225 (3) ◽  
pp. 679-699 ◽  
Author(s):  
W L Wang ◽  
X J Yang ◽  
G X Xu ◽  
Y Huang
Keyword(s):  
Design Optimization ◽  
High Speed ◽  
Optimal Result ◽  
Relief Valve ◽  
Valve System ◽  
Hydraulic Damper ◽  
Multi Objective ◽  
Damping Characteristics ◽  
Fitness Value ◽  
Optimization Search

Adjustable linear hydraulic dampers are widely used in high-speed trains to improve their ride comfort and stability, the distinctive damping characteristics of the dampers are intrinsically predetermined by their inner complete valve systems. Therefore, design of the complete valve system parameters for each damper type is of crucial importance. A multi-objective design optimization model for the concept of optimizing both the technical and economic capabilities of a three-valve complete valve system in a hydraulic damper was formulated, based on full damper dynamics modelling. A linear weighted criterion method was used to transform the established multi-objective problem to a single-objective problem, and a computer package employing the genetic algorithm for the optimization search was developed. Implementation of the design optimization was performed, and an optimal result, with about 10.29 per cent improvement of the overall fitness value, was obtained. Simulation results show that the optimal result satisfies all the competing objectives well within the constraints, except for some minor and tolerable tradeoffs in the relief valve response performance. Prototype experiments validated that the prototype dampers have obtained excellent damping characteristics, as expected. Thus, the complete valve system of the hydraulic damper was comprehensively optimized, with respect to both the technical and economic concerns. The approach developed in this work has already been applied to the engineering design of several hydraulic damper products in industry.

Experimental research into the low-temperature characteristics of a hydraulic damper and the effect on the dynamics of the pantograph of a high-speed train running in extreme cold weather conditions

2019 ◽  
Vol 234 (8) ◽  
pp. 896-907
Author(s):  
Wenlin Wang ◽  
Yuwen Liang ◽  
Weihua Zhang ◽  
Simon Iwnicki
Keyword(s):  
Low Temperature ◽  
Experimental Research ◽  
High Speed ◽  
Weather Conditions ◽  
Cold Weather ◽  
Temperature Characteristics ◽  
Hydraulic Damper ◽  
Damping Characteristics ◽  
High Speed Trains ◽  
Extreme Cold

There is likely to be a demand to run high-speed trains in extreme cold weather conditions in the near future; therefore, it is important to study the change in the characteristics of the materials and components in an extreme cold environment and their effects on the vehicle system dynamics. Experimental research into the low temperature characteristics of a pantograph hydraulic damper was carried out in this study. The results show that low temperature causes an increase in damping forces, and when the temperature is above the boundary temperature range, most indices of the damping capability increase with the decrease of temperature; when the temperature is below the boundary temperature range, most indices decrease with the decrease of temperature. Key parameters are identified to obtain the theoretical description of low-temperature damping characteristics using a simplified-parametric damper model and the experimental data. A mathematical model of the pantograph–catenary system incorporating the pantograph damper model is then established to calculate the effect of the damper performance on the pantograph dynamics low temperatures. Simulation results show that the lowering performance of the pantograph deteriorates noticeably due to the unstable low-temperature damping characteristics, but the deterioration of the raising performance and contact quality of the pantograph due to the low-temperature characteristics of the damper are less obvious. The results obtained in this study are valuable for understanding the low-temperature characteristics of a hydraulic damper, and instructive in the optimal specification of the pantograph damper for high-speed trains running in cold weather conditions.

Characterization and Optimization of Berdut Technology for a Magnetically Levitated Train

2005 ◽  
Author(s):  
Ezequiel Medici ◽  
David Serrano ◽  
Jeffrey Robles
Keyword(s):  
High Speed ◽  
Permanent Magnets ◽  
Magnetic Levitation ◽  
Linear Motor ◽  
High Speed Train ◽  
Damping Characteristics ◽  
Levitation System ◽  
Magnetic Levitation System ◽  
Working Principle ◽  
Stiffness And Damping

Berdut Technology is a novel magnetic levitation system suitable for high speed train applications. This technology combines magnets and electromagnets to obtain levitation and propulsion. A Berdut array of permanent magnets is used to provide the levitation via skates that are located on both sides of the vehicle. Both the rails and the skates are based on permanent magnets therefore no energy is required for levitation. A linear motor located along the center of the vehicle provides the propulsion. Both, skate and linear motor use the same concept and working principle. The paper is divided into two parts: the first part describes the skate levitation, while the second part describes the linear motor. Finite element method was chosen to model and simulate both the skate levitation and the linear motor. Energy dissipation resulting from hysteresis and eddy current losses in the skate was determined. Stiffness and damping characteristics for the levitation skates are presented and validated. The efficiency and thrust force for the linear motor model are also presented along with experiments performed to validate the simulations. Once, validated the models are used to design a Maglev suspension and a linear motor for high-speed train applications.

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