Considerations on Dynamic Contact Force with Catenary for the EP3 Pantograph

2015 ◽  
Vol 809-810 ◽  
pp. 1121-1126 ◽  
Author(s):  
Ioan Sebeşan ◽  
Sorin Arsene
Keyword(s):  
Contact Pressure ◽  
Contact Force ◽  
Contact Line ◽  
Power Supply ◽  
High Performance ◽  
Dynamic Contact ◽  
The Body ◽  
Vertical Movements ◽  
Current Collection ◽  
Force Variation

Power supply the energy needed for locomotives and electric trains is performed by means of pantographs on the bodywork. These high performance producing vehicles in so far as the contact between the collector (pantograph) and the catenary (contact line) is achieved and maintained regardless of speed. Thanks to the constructive type of the pantograph and the location of the contact force varies in relation to speed and can give rise to phenomena of oscillators that enhances the vertical movements of the wire feeder. As such the problem is essential for a good current collection is dynamic in nature. The most favorable way of current collection is achieved when between full and contact wire can maintain contact through a permanent and constant contact, a situation difficult to achieve in practice because of the first bump of the contact line. Juddering movements in vehicle while walking to a modification of the contact pressure which, however, it was found that is negligible in relation to the wave-like movements of the contact line. This article has looked at what is the dynamic contact force variation where the pantograph is located on the body of the locomotive EP3 LE 060 EA of 5100 kW. For this I started from the constructive characteristics of the components of the pantograph.

1⁄4 Car Model for Suspension Trim Corrector Performances Evaluation

2016 ◽  
Vol 823 ◽  
pp. 205-210
Author(s):  
Adrian Ioan Niculescu
Keyword(s):  
Contact Force ◽  
Harmonic Functions ◽  
Degrees Of Freedom ◽  
The Body ◽  
Vertical Acceleration ◽  
Vertical Movements ◽  
The Road ◽  
Quarter Car Model ◽  
Car Model ◽  
Quarter Car

The paper presents a complex quarter car model obtained with ADAMS software, View module, useful in the first stage of suspension dimensioning and optimization.The model is equipped with compression and rebound stopper buffer and suspension trim corrector.The proposed quarter car model with two degrees of freedom (wheel and body) performs all these goals allowing changing:Geometrical elementsPosition of equilibrium, depending on vehicle load;Trim correction;Elastic and dissipative characteristics of the suspension and tire;Suspension stroke;Road profile, assessed either by simple or summation of harmonic functions or reproducing real roadsBuffers (for stroke limitation) position and characteristics;The models developed provide information on:Vertical stability assessed by vertical movements of the body and the longitudinal and transversal stability evaluated based on adherence characterized by wheel ground contact force and frequency of soil detachment wheel.Comfort assessed on the basis of body vertical acceleration and collision forces to the stroke ends.The body-road clearanceThe trim corrector efficiencyAll above performances evaluated function the road unevenness, acceleration, deceleration, turning regime.The damping characteristic is defined by damping forces at different speed for each strokes respectively one for rebound and other for compression.The contact force road-wheel is defined based tire rigidity law.The stopper buffer forces on rebound and compression are defined based each specific rigidity characteristics.The road excitation is realized with a function generator.The software allow the model evolution visualisation in real time, also generating the diagrams of displacements, forces, accelerations, speeds, for each elements or for relative evolution between diverse elements.The simulation was realized for unloaded and fully loaded car using a road generated by a sum of harmonic functions presented in equation (8).The excitation covers the specific frequencies area, being under the body frequencies up to the wheel proper frequencies.The realized ¼ car model, have reached the goal to evaluate the suspension trim correction advantages.The simulations confirm the trim corrector increases the suspension performances, thus for the analyzed case the trim corrector increase simultaneous:Body-ground clearance (evaluated by body higher increasing) between 18.5÷55.1 %Body stability (evaluated by maximal body displacement) between 9.8÷11.4 %Body comfort (evaluated by maximal body acceleration) between 3.4÷35.5 %Adherence (evaluated by maximal and RMS wheel-groundcontact force variation) between 7.0÷12.1 %Body and axles protection (evaluated by buffer strike force) between 10.8÷38.2 %

Computer Evaluation of Controlled Pantographs for Current Collection From Simple Catenary Overhead Equipment at High Speed

1983 ◽  
Vol 105 (4) ◽  
pp. 287-294 ◽  
Author(s):  
T. Vinayagalingam
Keyword(s):  
Contact Force ◽  
High Speed ◽  
Overhead Line ◽  
Combined System ◽  
Current Collection ◽  
Constant Height ◽  
Force Profile ◽  
Force Variation ◽  
Computer Simulation Technique

A digital computer simulation technique is used to study the effects of changing pantograph characteristics upon the quality of current collection from simple catenary overhead equipment at high speed. In particular, the likely benefits to be derived by the use of controlled pantographs are assessed. Pantograph performance is judged on the basis of contact force variation and displacement responses of pantograph and contact wire. These studies have shown that the dynamic displacements of the combined system are determined primarily by the overhead line parameters rather than by the pantograph. At higher speeds droppers in the vicinity of the pantograph slacken and this is seen to influence significantly the contact force profile. On a “constant height” overhead line, the proposed “frame compensated” and “panhead inertia compensated” pantographs do not show any marked improvement in the quality of current collection.

The Vertical Forces Introduced by Wind on the Active Pantograph from Bodywork of Locomotive LE 060 EA of 5100 kW

2015 ◽  
Vol 809-810 ◽  
pp. 1115-1120 ◽  
Author(s):  
Sorin Arsene
Keyword(s):  
Comparative Analysis ◽  
Power Supply ◽  
High Speed ◽  
High Performance ◽  
The Body ◽  
Vehicle Body ◽  
Aerodynamic Forces ◽  
Railway Vehicles ◽  
Railway Traction ◽  
Electric Railway

Gusts of wind with high speed can adversely affect the operation of the electric railway vehicles. These vehicles are able to move and to obtain a high performance, as long as the power supply is ensured. The variation of the vertical forces for maintaining contact between pantograph and catenary may cause interruption of the power supply of the electric railway traction vehicles. The placement of the capture equipment on the vehicle body determines appearance of aerodynamic forces acting on it. To see which are the vertical forces introduced by wind on active capture equipment, used at locomotives LE 060 EA of 5100 kW, we considered the EP3 type of pantograph as model. This was modelled at scale 1:1 taking into account the placement on the body of the locomotive. For the simulation of wind we considered three point values of its speed (10 m/s, 20 m/s, 30 m/s) and angle of eight values that are within the range of 0 deg – 180 deg. With the results of the simulation we have done a comparative analysis on the additional vertical forces introduced by wind for the cases analyzed.

scholarly journals Cardboard Bed Without Mattress Is Ineffective in Improving the body Contact Pressure-a Preliminary Study Using a Dummy Model

2021 ◽  
Vol 58 ◽  
pp. 004695802110656
Author(s):  
Seiji Hamanishi
Keyword(s):  
Contact Pressure ◽  
Body Surface ◽  
High Performance ◽  
The Body ◽  
Whole Body ◽  
Future Research ◽  
Scientific Validity ◽  
Body Contact ◽  
Surface Contour ◽  
Preliminary Study

Objective This study aimed to describe and evaluate the dispersion of body-mattress contact pressure on a cardboard bed and investigate whether the cardboard bed has a positive effect on evacuees’ musculoskeletal burden. Materials and Methods A high-performance nursing simulator was used to measure the contact pressure and the body surface contour area of the bed, and these values were collected with the patient in the supine position using the Body Pressure Measurement System. Data of each test were acquired 10 times and were compared among 4 conditions (plastic sheet, cardboard bed, cardboard bed with a blanket, and cardboard bed with a mattress-topper). The data analysis for body-mattress contacts pressure and the surface contour area of the whole body, head, chest, and buttocks were conducted by one-way repeated analysis of variance and Bonferroni post-hoc test. Results The average body-contact pressure on the cardboard bed did not decrease compared with that on the floor with plastic sheets. In contrast, the body surface contour area was significantly different among any other conditions, but the gap was only approximately 16%. However, the body-contact pressure and the body surface contour area were improved when a mattress-topper was added on the cardboard bed. When a blanket was laid on the cardboard bed, the contact area was increased. Conclusion Our results indicate that the pressure dispersion ability of the cardboard bed was not sufficient; however, adding the mattress-topper or the blanket could contribute to an improvement in the evacuees’ musculoskeletal burden. Many evacuees lay a mattress topper or futon on a cardboard bed after installing cardboard beds. Our findings may also support the scientific validity of the evacuees’ actual sleeping style in Japan. This preliminary study provides the basis for future research on exploring an appropriate sleeping bed condition in evacuee shelters.

scholarly journals Effect of Pantograph’s Main Structure on the Contact Quality in High-Speed Railway

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Jiangwen Wang ◽  
Guiming Mei
Keyword(s):  
Contact Force ◽  
Structural Design ◽  
High Speed ◽  
Electrical Energy ◽  
Dynamic Contact ◽  
Sine Series ◽  
High Speed Railway ◽  
Main Structure ◽  
Current Collection ◽  
Relative Coordinates

In general, the electrical energy is provided to the high-speed train through the pantograph-catenary sliding contact. The variation of the dynamic contact force is expected to be small enough to keep the good current collection quality and to extend the service life of the pantograph-catenary system. In this paper, the two tension wires of the catenary are discretized by the sine-series expansions, a multibody dynamics theory based on relative coordinates is adopted to describe the dynamic behavior of the pantograph, and the standard deviation (STD) of dynamic contact force is used as the indicator to evaluate the contact quality. The objective is to investigate how the variations of the pantograph’s main structure influence the contact quality, which may support the structural design and parameter optimization of the pantograph in high-speed railway.

Two Contrasting Versions of the Optimal Active Vehicle Suspension

1986 ◽  
Vol 108 (3) ◽  
pp. 264-268 ◽  
Author(s):  
Dean Karnopp
Keyword(s):  
Contact Force ◽  
The Body ◽  
Body Motion ◽  
Performance Indices ◽  
Active Suspensions ◽  
Vehicle Suspensions ◽  
State Variable ◽  
Force Variation ◽  
Feedback Laws ◽  
Suspension Performance

It is generally agreed that vehicle suspensions should isolate the body from roadway unevenness inputs but it is less clear on which other functions are most important. Some studies focus on keeping the wheel-road contact force excursions as small as possible for safety reasons and others focus on limiting the main suspension deflection for good rigid body motion control. In this paper, two performance indices are used which lead to optimal state variable feedback laws for the suspension force. Body isolation is traded off in one case against contact force variation and in the other against suspension deflection. The use of symmetric root locus sketches shows the types of system that result in both cases. It is shown that optimal active suspensions designed according to different criteria are not necessarily comparable and it may not be fair to compare an optimal suspension with a conventional one, unless all aspects of suspension performance are considered simultaneously.

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