Prediction of the Pantograph/Catenary Wear Using Nonlinear Multibody System Dynamic Algorithms

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Siripong Daocharoenporn ◽  
Mongkol Mongkolwongrojn ◽  
Shubhankar Kulkarni ◽  
Ahmed A. Shabana
Keyword(s):  
Multibody System ◽  
Electrical Contact ◽  
Efficient Solutions ◽  
Electrical Contact Resistance ◽  
Contact Wire ◽  
Wear Rates ◽  
Simulation Techniques ◽  
Contact Formulation ◽  
Acceleration And Deceleration ◽  
Electrical Wear

In this investigation, computational multibody system (MBS) algorithms are used to develop detailed railroad vehicle models for the prediction of the wear resulting from the pantograph/catenary dynamic interaction. The wear is predicted using MBS algorithms for different motion scenarios that include constant-speed curve negotiation and acceleration and deceleration on a tangent (straight) track. The effect of the vehicle vibration in these different motion scenarios on the contact force is further used to study the wear rates of the contact wire. The wear model used in this investigation accounts for the electrical and the mechanical effects. The nonlinear finite element (FE) absolute nodal coordinate formulation (ANCF), which is suitable for implementation in MBS algorithms, is used to model the flexible catenary system, thereby eliminating the need for using incremental-rotation procedures and co-simulation techniques. In order to obtain efficient solutions, both the overhead contact line and the messenger wire are modeled using the gradient-deficient ANCF cable element. The pantograph/catenary elastic contact formulation employed in this study allows for separation between the pantograph panhead and the contact wire, and accounts for the effect of friction due to the sliding between the pantograph panhead and the catenary cable. The approach proposed in this investigation can be used to evaluate the electrical contact resistance, contribution of the arcing resulting from the panhead/catenary separation, mechanical and electrical wear contributions, and the effect of the pantograph mechanism uplift force on the wear rate. Numerical results are presented and analyzed to examine the wear rates for different motion scenarios.

Pantograph/Catenary Wear Using Multibody System Dynamic Algorithms

2020 ◽  
Author(s):  
Siripong Daocharoenporn ◽  
Mongkol Mongkolwongrojn ◽  
Shubhankar Kulkarni ◽  
Ahmed A. Shabana
Keyword(s):  
Electrical Contact ◽  
Electrical Contact Resistance ◽  
Wear Model ◽  
Contact Wire ◽  
Wear Rates ◽  
Simulation Techniques ◽  
Contact Formulation ◽  
Acceleration And Deceleration ◽  
Electrical Wear ◽  
Railroad Vehicle

Abstract In this investigation, computational multibody systems (MBS) algorithms are used to develop detailed railroad vehicle models for the prediction of the wear resulting from the pantograph/catenary dynamic interaction. The catenary wear is predicted for different motion scenarios that include constant-speed curve negotiation, and acceleration and deceleration on a tangent (straight) track. The effect of the vehicle vibration in these different motion scenarios on the contact force is further used to study the wear rates of the contact wire. The wear model used in this investigation accounts for the electrical and the mechanical effects. The nonlinear finite element (FE) absolute nodal coordinate formulation (ANCF), which is suitable for implementation in MBS algorithms, is used to model the flexible catenary system, thereby eliminating the need for using incremental rotation procedures and co-simulation techniques. The pantograph/catenary elastic contact formulation employed in this study allows for separation between the pantograph pan-head and the contact wire, and accounts for the effect of friction due to the sliding between the pantograph pan-head and the catenary cable. The approach proposed in this investigation can be used to evaluate the electrical contact resistance, contribution of the arcing resulting from the pan-head/catenary separation, mechanical and electrical wear contributions, and effect of the pantograph mechanism uplift force on the wear rate.

The fretting corrosion of mild steel

1956 ◽  
Vol 236 (1206) ◽  
pp. 411-425 ◽  
Keyword(s):  
Mild Steel ◽  
Electrical Contact ◽  
Fretting Corrosion ◽  
Electrical Contact Resistance ◽  
Wear Rates ◽  
Wide Range ◽  
Simple Rules ◽  
Frictional Forces ◽  
Number Of Cycles ◽  
Unidirectional Motion

A quantitative investigation of the fretting corrosion of mild-steel specimens is described. Measurements have been made of the frictional forces, the degree of damage and the variations in the electrical contact resistance for a wide range of applied loads, vibration amplitudes and number of cycles of motion. In addition, the nature of the fretting corrosion scars and debris has been examined using optical and electron microscopy and electron diffraction. The same sequence of phenomena is observed under all conditions, namely, (i) the formation of intermetallic welds, (ii) the production of black α-Fe 2 O 3 particles and ultimately (iii) the production of fine red-brown α-Fe 2 O 3 particles. However, the magnitude of the frictional forces, the wear rates and the contact resistances are greatly dependent upon the amplitude of vibration. At large amplitudes large intermetallic junctions form soon after the onset of motion and the friction rapidly rises above its initial value. Subsequently the friction drops to a very low value, μ ~ 0·05; this is due to the presence of loose oxidized debris which accumulates and tends to roll between the rubbing contacts. At small amplitudes the scale of the welding is so reduced that no perceptible rise in friction occurs before the friction falls to its final low value. Measurements of the depths of damage in the scars show that the holes which form arise from the original welding mechanism and that they subsequently disappear. At large amplitudes the wear rates obey the same simple rules of wear as are obeyed in unidirectional motion, namely, the wear is proportional to the distance of sliding; the wear rate is proportional to the load and independent of the apparent area of contact. Further-more, there is close agreement in the magnitude of the wear rates in unidirectional motion and during fretting at large amplitudes. At small amplitudes, however, much smaller rates of damage are obtained.

scholarly journals The Route for Ultra-High Recording Density Using Probe-Based Data Storage Device

NANO ◽  
2015 ◽  
Vol 10 (08) ◽  
pp. 1550118 ◽  
Author(s):  
Lei Wang ◽  
Jing Wen ◽  
CiHui Yang ◽  
Shan Gai ◽  
YuanXiu Peng
Keyword(s):  
Phase Change ◽  
Data Storage ◽  
Electrical Contact ◽  
Crystal Nucleation ◽  
Access Time ◽  
Storage Device ◽  
Electrical Contact Resistance ◽  
Low Energy Consumption ◽  
Modeling Techniques ◽  
Second Period

Phase-change probe memory using Ge2Sb2Te5 has been considered as one of the promising candidates as next-generation data storage device due to its ultra-high density, low energy consumption, short access time and long retention time. In order to utmostly mimic the practical setup, and thus fully explore the potential of phase-change probe memory for 10 Tbit/in2 target, some advanced modeling techniques that include threshold-switching, electrical contact resistance, thermal boundary resistance and crystal nucleation-growth, are introduced into the already-established electrothermal model to simulate the write and read performance of phase-change probe memory using an optimal media stack design. The resulting predictions clearly demonstrate the capability of phase-change probe memory to record 10 Tbit/in2 density under pico Joule energy within micro second period.

Discrete drops in the electrical contact resistance during nanoindentation of a bulk metallic glass

2016 ◽  
Vol 108 (18) ◽  
pp. 181903 ◽  
Author(s):  
Gaurav Singh ◽  
R. L. Narayan ◽  
A. M. Asiri ◽  
U. Ramamurty
Keyword(s):  
Metallic Glass ◽  
Contact Resistance ◽  
Bulk Metallic Glass ◽  
Electrical Contact ◽  
Electrical Contact Resistance

scholarly journals The Wear Process During the “Running-In” of Steel in Lubricated Sliding

1987 ◽  
Vol 109 (4) ◽  
pp. 587-591 ◽  
Author(s):  
M. Suzuki ◽  
K. C. Ludema
Keyword(s):  
Contact Resistance ◽  
Surface Film ◽  
Electrical Contact ◽  
Mineral Oil ◽  
Entrance Region ◽  
Engine Oil ◽  
Small Range ◽  
Electrical Contact Resistance ◽  
Metallic Contact ◽  
Wear Process

Steel cylinders were slid against flat steel disks, using a liquid lubricant, in order to study the progression of events associated with “running-in.” It was found that, when using mineral oil, the electrical contact resistance varied over a small range of high values indicating no metallic contact, whereas with engine oil a high resistance with an intermittent negligible contact resistance was found. A surface film forms from the additives in the engine oil which produces lower wear, slightly higher friction, a retarded running-in, and a rougher surface finish in the direction of sliding than does the mineral oil. A film which is composed only of Fe3O4 is formed when mineral oil is used. In addition, the mineral oil lubricated surfaces develop a conforming waviness across the sliding tracks. The oxide must have enhanced this surface conformity since it was not seen in the surfaces lubricated with engine oil. The role of the oxide may be further seen in experiments in which wear debris that accumulated in the entrance region of specimen contact was removed at frequent intervals. Little conforming waviness was seen in the latter case, suggesting that oxide which gathered in the entrance region abraded grooves in the steel surfaces. After the oxides were dislodged the friction increased and the contact resistance decreased for a time, indicating that the oxide acted like a solid lubricant.

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