A Study on Dynamic Behaviour of Pantographs by Using Hybrid Simulation Method

2005 ◽  
Vol 219 (3) ◽  
pp. 189-199 ◽  
Author(s):  
W H Zhang ◽  
G M Mei ◽  
X J Wu ◽  
L Q Chen
Keyword(s):  
Dynamic Behaviour ◽  
Dynamic Performance ◽  
Hybrid Simulation ◽  
Simulation Method ◽  
Test Facility ◽  
Simulation Test ◽  
Test Device ◽  
Set Up ◽  
Stiffness And Damping ◽  
Hardware Test

To study the dynamic behaviour of pantographs, a hybrid simulation method has been used. A special test facility, which is used to simulate the dynamic performance of a pantograph when it runs through the overhead line, is established and described in this paper. As the catenary is difficult to be modelled by a hardware test facility indoor, a mixed theoretical-experimental technique is used in test facility. On the basis of the set-up of hybrid simulation test device of the pantograph-catenary system, the dynamic behaviours of four types of pantographs running along the overhead equipment at different running speeds are examined and compared. Meanwhile, the dynamic parameters such as mass, stiffness, and damping of four pantographs are measured using the hybrid simulation test facility. On the basis of these parameters, the dynamic behaviours of the four pantographs are analysed.

Dynamic characteristics of squeeze-type mount using magnetorheological fluid

2005 ◽  
Vol 219 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Y K Ahn ◽  
J-Y Ha ◽  
Y-H Kim ◽  
B-S Yang ◽  
M Ahmadian ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Experimental Analysis ◽  
Vibration Isolation ◽  
Dynamic Behaviour ◽  
Electrical Current ◽  
Magnetorheological Fluid ◽  
Test Set ◽  
Mr Fluid ◽  
Set Up ◽  
Stiffness And Damping

This paper presents an analytical and experimental analysis of the characteristics of a squeeze-type magnetorheological (MR) mount which can be used for various vibration isolation areas. The concept of the squeeze-type mount and details of the design of a squeeze-type MR mount are discussed. These are followed by a detailed description of the test set-up for evaluating the dynamic behaviour of the mount. A series of tests was conducted on the prototype mount built for this study, in order to characterize the changes occurring as a result of changing electrical current to the mount. The results of this study show that increasing electrical current to the mount, which increases the yield stress of the MR fluid, will result in an increase in both stiffness and damping of the mount. The results also show that the mount hysteresis increases with increase in current to the MR fluid, causing changes in stiffness and damping at different input frequencies.

Dynamic-Performance Research of Placement Machine

2010 ◽  
Vol 44-47 ◽  
pp. 641-645 ◽  
Author(s):  
Yong Shan Xiao ◽  
Fu Min Song ◽  
Qiang Fang
Keyword(s):  
Working Conditions ◽  
Dynamic Performance ◽  
Simulation Method ◽  
Structure Form ◽  
Dynamic Accuracy ◽  
Controlling System ◽  
Placement Machine ◽  
Stiffness And Damping ◽  
The Impact ◽  
Performance Research

The placement machine was simulated by multidisciplinary co-simulation method in various working conditions, and its dynamic accuracy was studied by simulation. According to the structure form of the placement machine, the virtual prototype for co-simulation was built. The impact of all sorts of parameters on the system dynamic accuracy was simulated including the stiffness and damping of the slider and the shaft coupling, the friction coefficient and the mass distribution etc. The result shows this method is able to predict the dynamic performance and the control margin of the whole machine, instruct the design optimization and the selection, and provide the good design thought and direction for the matching design of the machinery and controlling system.

Optimized Simulation Method and Experimental Verification on Dynamic Analysis of a Light Truck Frame

2009 ◽  
Author(s):  
Feng Gao ◽  
Yonghua Xiong ◽  
Lei Tian ◽  
Farong Du ◽  
Guoyan Xu
Keyword(s):  
Geometric Model ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Element Model ◽  
Simulation Method ◽  
Frame Structure ◽  
Light Truck ◽  
Combined Simulation ◽  
Set Up ◽  
Beam Frame

The three-dimensional geometric model of the fringe-beam frame had been built based on the frame structure of a light truck. In order to optimize the frame structure, the finite element model of the frame and the suspension system were set up. Considering the influence of suspension on frame dynamic performance, the modal properties of the frame model was analyzed in the commercial analysis program ANSYS, using two different methods. Based on the experiments, it was verified that combining MPC184 elements and spring elements Combin14 is a better way to simulate suspension compared to using spring finite elements only. Furthermore, the combined simulation results coincide with experimental modal analysis results, which were conducted thereafter. Subsequently, the frame stress-strain distribution rules and dynamics response were calculated under the random road spectrum excitation, and the frame dynamic parameters were obtained. This study provides some theoretical bases for frame structure improvement, and proposes an optimum method to simulate suspension. The results have direct significance in ensuring the stability, comfort and reliability of a light truck frame.

scholarly journals Dynamic behaviour and stability analysis of a compensated aerostatic pad

2021 ◽  
Vol 312 ◽  
pp. 05003
Author(s):  
Federico Colombo ◽  
Luigi Lentini ◽  
Terenziano Raparelli ◽  
Andrea Trivella ◽  
Vladimir Viktorov
Keyword(s):  
Dynamic Behaviour ◽  
Numerical Study ◽  
Dynamic Performance ◽  
Low Friction ◽  
Lumped Model ◽  
Positioning Systems ◽  
Diaphragm Valve ◽  
Bearing Stiffness ◽  
The Stability ◽  
Stiffness And Damping

Thanks to their low friction, aerostatic pads have important applications in precision positioning systems and linear guides. A simple and cheap solution to increase the static stiffness of aerostatic pads is to add a proper designed pneumatic valve to regulate the air flow supplied to the bearing. However, integrating aerostatic pads with additional devices can reduce its dynamic performance. This paper presents a numerical study on the dynamic behaviour and stability a commercial aerostatic pad controlled by a custom-built diaphragm valve. The bearing performance is studied by means of a lumped parameters model. Air bearing stiffness and damping are analysed in the frequency domain. Subsequently, the lumped model is linearized to investigate the stability of the system by means of Routh-Hurwitz method. The performance of the controlled air pad is compared to that of a simple commercial air pad.

Wave propagation improvement in two-dimensional bond-based peridynamics model

2021 ◽  
pp. 095440622098555
Author(s):  
Reza Alebrahim ◽  
Pawel Packo ◽  
Mirco Zaccariotto ◽  
Ugo Galvanetto
Keyword(s):  
Wave Propagation ◽  
Dynamic Performance ◽  
Numerical Dispersion ◽  
Motion Modeling ◽  
Minimization Method ◽  
Irregular Wave ◽  
Point Collocation ◽  
Potential Applications ◽  
Non Local ◽  
Set Up

In this study, methods to mitigate anomalous wave propagation in 2-D Bond-Based Peridynamics (PD) are presented. Similarly to what happens in classical non-local models, an irregular wave transmission phenomenon occurs at high frequencies. This feature of the dynamic performance of PD, limits its potential applications. A minimization method based on the weighted residual point collocation is introduced to substantially extend the frequency range of wave motion modeling. The optimization problem, developed through inverse analysis, is set up by comparing exact and numerical dispersion curves and minimizing the error in the frequency-wavenumber domain. A significant improvement in the wave propagation simulation using Bond-Based PD is observed.

scholarly journals The Development of Electric Arc Fault Simulation Test Device

2013 ◽  
Vol 52 ◽  
pp. 297-301 ◽  
Author(s):  
Zi-bo Qi ◽  
Wei Gao ◽  
Ying-cong Zhang
Keyword(s):  
Fault Simulation ◽  
Electric Arc ◽  
Simulation Test ◽  
Test Device

scholarly journals Development of a hybrid simulation method for current collection systems, using a real-time multi degree-of-freedom catenary model

2018 ◽  
Vol 84 (867) ◽  
pp. 18-00229-18-00229
Author(s):  
Shigeyuki KOBAYASHI ◽  
Yoshitaka YAMASHITA ◽  
Takayuki USUDA ◽  
David P. STOTEN
Keyword(s):  
Real Time ◽  
Hybrid Simulation ◽  
Simulation Method ◽  
Degree Of Freedom ◽  
Current Collection

The Surface Roughness Effect on the Dynamic Stiffness and Damping Characteristics of the Hydrostatic Thrust Spherical Bearings: Part 5 of 5 — Clearance Type of Bearings

2007 ◽  
Author(s):  
Ahmad W. Yacout
Keyword(s):  
Surface Roughness ◽  
Capillary Tube ◽  
Dynamic Stiffness ◽  
Dynamic Performance ◽  
Major Effect ◽  
Design Parameters ◽  
Compressibility Effect ◽  
Damping Coefficients ◽  
Stiffness And Damping ◽  
Fluid Compressibility

This study has theoretically analyzed the surface roughness, centripetal inertia and recess volume fluid compressibility effects on the dynamic behavior of a restrictor compensated hydrostatic thrust spherical clearance type of bearing. The stochastic Reynolds equation, with centripetal inertia effect, and the recess flow continuity equation with recess volume fluid compressibility effect have been derived to take into account the presence of roughness on the bearing surfaces. On the basis of a small perturbations method, the dynamic stiffness and damping coefficients have been evaluated. In addition to the usual bearing design parameters the results for the dynamic stiffness and damping coefficients have been calculated for various frequencies of vibrations or squeeze parameter (frequency parameter) and recess volume fluid compressibility parameter. The study shows that both of the surface roughness and the centripetal inertia have slight effects on the stiffness coefficient and remarkable effects on the damping coefficient while the recess volume fluid compressibility parameter has the major effect on the bearing dynamic characteristics. The cross dynamic stiffness showed the bearing self-aligning property and the ability to oppose whirl movements. The orifice restrictor showed better dynamic performance than that of the capillary tube.

Dynamic Characterization of an Integral Squeeze Film Bearing Support Damper for a Supercritical CO2 Expander

2017 ◽  
Author(s):  
Bugra Ertas ◽  
Adolfo Delgado ◽  
Jeffrey Moore
Keyword(s):  
High Speed ◽  
Dynamic Performance ◽  
Mechanical Impedance ◽  
Squeeze Film ◽  
Fluid Inertia ◽  
Inertia Effects ◽  
Damping Behavior ◽  
Impedance Testing ◽  
Stiffness And Damping ◽  
Onset Of Cavitation

The present work advances experimental results and analytical predictions on the dynamic performance of an integral squeeze film damper (ISFD) for application in a high-speed super-critical CO2 (sCO2) expander. The test campaign focused on conducting controlled orbital motion mechanical impedance testing aimed at extracting stiffness and damping coefficients for varying end seal clearances, excitation frequencies, and vibration amplitudes. In addition to the measurement of stiffness and damping; the testing revealed the onset of cavitation for the ISFD. Results show damping behavior that is constant with vibratory velocity for each end seal clearance case until the onset of cavitation/air ingestion, while the direct stiffness measurement was shown to be linear. Measurable added inertia coefficients were also identified. The predictive model uses an isothermal finite element method to solve for dynamic pressures for an incompressible fluid using a modified Reynolds equation accounting for fluid inertia effects. The predictions revealed good correlation for experimentally measured direct damping, but resulted in grossly overpredicted inertia coefficients when compared to experiments.

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