Performance Evaluation of a Novel Optical Sensing System for Detecting Rail Lubricity Conditions

2021 ◽  
Author(s):  
Yu Pan ◽  
Timothy Mast ◽  
Carvel Holton ◽  
Mehdi Ahmadian
Keyword(s):  
Optical Sensing ◽  
Laboratory Evaluation ◽  
Controlled Environment ◽  
Contact Method ◽  
Dynamic Tests ◽  
Friction Modifiers ◽  
Sensing System ◽  
Ultraviolet Wavelength ◽  
The Coefficient Of Friction ◽  
Static And Dynamic Tests

Abstract This paper presents a laboratory evaluation of a novel optical sensing system mounted on a moving platform for detecting the presence and adequacy of Top-of-Rail (TOR) friction modifiers and flange greases. The friction modifiers are applied on the top of rail for managing the coefficient of friction to reduce wear while maintaining stable traction. Flange greases are intended to reduce wear that happens when wheel flange makes contact with the rail gage-face during curving. Additionally, friction modifiers and flange greases could influence fuel consumption. The U.S. railroads have made the application of TOR adopted on the mainlines. The tools, however, for evaluating the rail lubricity condition are limited and there is often uncertainty about the required or “optimal” amount of friction modifiers, except for the trained eye of the track engineer. The proposed sensing system provides an innovative non-contact method by using the optical laser’s reflective and scattering properties when directed at the rail surface to assess the friction modifiers’ conditions. In addition, the laser’s near-UV (Ultraviolet) wavelength is able to excite fluorescent elements in the flange grease and detect any top-of-rail contamination of grease that may exist. The design and working principles of the system are demonstrated and explained in this paper. Static and dynamic tests are performed in the lab under a controlled environment for various lubricity conditions, in order to experimentally validate and evaluate the performance of the optical sensing system. The lab evaluation indicates that the proposed optical sensing system is capable of successfully detecting the diverse lubricity conditions and shows a great potential to be widely tested and used in the field on revenue-service tracks.

The effect of the indenter elasticity on the Hertzian fracture of brittle materials

1973 ◽  
Vol 334 (1596) ◽  
pp. 95-117 ◽  
Keyword(s):  
Fracture Stress ◽  
Opposite Effect ◽  
Test Material ◽  
Test Surface ◽  
Dynamic Tests ◽  
Frictional Forces ◽  
Consistent Increase ◽  
Static And Dynamic Tests ◽  
Ring Crack ◽  
Ring Cracks

A spherical indenter loaded statically or dynamically into contact with the surface of a brittle material produces a well-defined ring crack. This phenomenon, when interpreted by the Hertz theory of elastic contact, provides a convenient test for the strength of the material. If the elastic modulus of the indenter is different from that of the test material, e. g. a steel indenter in contact with a glass surface, frictional forces are brought into play at the interface which modify the Hertz distribution of contact stress. This effect has been examined both theo­retically and experimentally. An indenter which is more rigid than the test surface is shown to lead to an apparent increase in fracture strength of the material, a less rigid indenter has the opposite effect. Static and dynamic tests of plate glass showed a consistent increase in apparent fracture stress of about 50 % using spherical steel indenters compared with glass indenters. This increase agrees well with the influence of friction upon the Hertzian stress calculated theoretically. The average radius of the ring cracks produced by steel indenters was observed to be greater than that produced by glass indenters, an effect of friction also predicted by the theory. Secondary ring cracks of smaller radius have frequently been observed during unloading of a steel indenter. These were not found when a glass indenter was used and an explanation is suggested in terms of the frictional effect which arises from a difference in elasticity between the indenter and the test surface.

Evaluation Method of U-Bolt Energy Absorption

2009 ◽  
Author(s):  
Eiji Shirai ◽  
Tetsuya Zaitsu ◽  
Kazutoyo Ikeda ◽  
Toshiaki Yoshii ◽  
Masami Kondo ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Evaluation Method ◽  
Design Procedure ◽  
Piping System ◽  
Design Technique ◽  
Dynamic Tests ◽  
Key Issues ◽  
Static And Dynamic Tests ◽  
Force Displacement ◽  
Rigid Design

At domestic PWR plants in Japan, one of the major key issues is earthquake-proof safety [1–3]. Recently, a design procedure using energy absorption, not conventional rigid design, was authorized according to revised review guidelines for aseismic design (JEAC4601). Therefore, we focused on the design technique that utilizes energy absorption effects to reduce the seismic responses of the piping system with U-Bolt, by the static and dynamic tests of simplified piping model supported by U-Bolt. The force-displacement characteristics and a fatigue diagram were obtained by the tests.

Inspection and Model Experiment of a Damaged Arch Bridge

2007 ◽  
Vol 340-341 ◽  
pp. 223-228
Author(s):  
Ying Fang Fan ◽  
Zhi Qiang Hu ◽  
Jing Zhou
Keyword(s):  
Model Experiment ◽  
Dynamic Test ◽  
Dynamic Responses ◽  
Dynamic Tests ◽  
Arch Bridge ◽  
Mechanical Responses ◽  
Organic Glasses ◽  
Bridge Model ◽  
Static And Dynamic Tests ◽  
Good Agreement

The structural behavior of an old six-span reinforced concrete arch bridge, which has been in service for about 40 years, is investigated. Field monitoring (inclusive of test of material property, static and dynamic test of the bridge) was conducted, static and dynamic responses of the bridge are obtained. Based on the primitive bridge, a scaled one-span bridge model was fabricated by organic-glasses. Both the static and dynamic tests were executed on the bridge model in the laboratory. Since the arch rib is the crucial member for the arch bridge, 7 notches were cut on both arch ribs of the bridge model to simulate different damages of the arch rib. Mechanical responses of the bridge with different damages on the arch ribs were achieved. FEM analyses were preformed on the bridge as well. Numerical results show good agreement with the experimental results.

Load capacity assessment of “Antonio Dovali Jaime” bridge using static and dynamic tests

2008 ◽  
pp. 85-85
Author(s):  
V Robles ◽  
M Ruiz-Sandoval ◽  
J Téllez ◽  
F Burgos ◽  
O Ortiz ◽  
...  
Keyword(s):  
Load Capacity ◽  
Capacity Assessment ◽  
Dynamic Tests ◽  
Static And Dynamic Tests

Measurement of the Elastic Moduli of Structural Adhesives by a Resonant Bar Technique

1976 ◽  
Vol 18 (3) ◽  
pp. 149-158 ◽  
Author(s):  
R. D. Adams ◽  
J. Coppendale
Keyword(s):  
Thin Film ◽  
Elastic Moduli ◽  
Dynamic Tests ◽  
Structural Adhesives ◽  
Young’S Moduli ◽  
Epoxy Adhesives ◽  
Dynamic Torsion ◽  
Static And Dynamic Tests

A method of measuring the dynamic torsion and Young's moduli of a thin film of adhesive is described. The accuracy of the technique and its suitability for structural adhesives is discussed. Values of modulus obtained using this method are compared with values obtained from static and dynamic tests on bulk specimens of three epoxy adhesives.

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