Brake Shoes and Thermal Mechanical Shelling

Author(s):  
Scott M. Cummings ◽  
Tom McCabe ◽  
Dan Gosselin

The Wheel Defect Prevention Research Consortium (WDPRC) conducted a review of existing brake shoe tests to explore the combinations of brake shoe force, time, and wheel/brake shoe coefficient of friction (COF) needed to achieve the temperatures of concern for thermal mechanical shelling (TMS). Data was found involving normally expected brake shoe forces applied to a dynamometer wheel and a variety of test parameters and procedures. All temperatures were measured using a sliding thermocouple pressed lightly against the wheel tread. All testing reported involved new brake shoes that may have different COF properties from used brake shoes. Tests included brake shoe tests conducted in accordance with the Association of American Railroads (AAR) M-926 specification, constant horsepower tests, and simulated stuck brake tests. Tread conditioning brake shoes were investigated, as well as high friction composition brake shoes. Findings from these tests include the following: • Tread conditioning brake shoes produced lower wheel tread temperatures compared to high-friction composition brake shoes. The magnitude of this difference varied depending on the test conditions; • In the dynamometer test most closely simulating revenue service conditions, 37 kW (50 hp) was required to heat wheels above 316°C (600°F); • Different models of high-friction composition brake shoes produced similar wheel temperatures under the parameters of the AAR M-926 tests. The range of average wheel temperatures produced by different models of high-friction composition brake shoes was only about 28°C (50°F) at any point during the test; • Individual brake shoes of the same model usually produced consistent results with respect to wheel temperature. Two exceptions to this statement were observed in the AAR M-926 test results. In a laboratory dynamometer test involving service damaged wheels, the WDPRC was unable to produce any measurable reduction in wheel tread defect size through the application of tread conditioning brake shoes. However, four service trials of tread conditioning brake shoes showed potential benefits in using tread conditioning brake shoes to reduce the number of wheelsets removed for tread damage.

Author(s):  
Scott Cummings

The Wheel Defect Prevention Research Consortium (WDPRC) has conducted a review and analysis of existing literature and existing data related to brake shoe force (BSF) variation in freight car brake rigging. This work was conducted to explore the sources of BSF variation, define the expected amount of BSF variation, and describe some of the existing brake system designs that may help reduce the amount of BSF variation. Wheel temperature is related to BSF due to the use of the wheel tread as a brake drum. Variation in BSF within a given railcar is one potential source of elevated wheel temperatures and thermal mechanical shelling (TMS) damage to the wheels. At elevated temperatures, wheels become less resistant to fatigue damage due to changes in the material mechanical properties and relief of beneficial residual stresses. Data recorded by a wayside wheel temperature detector shows that eliminating wheel temperature differences within individual cars could reduce the number of wheels reaching temperatures of concern for TMS by a factor of eight.


Author(s):  
Scott Cummings ◽  
Tom McCabe ◽  
Glenn Guelde ◽  
Dan Gosselin

A series of dynamometer tests were conducted by the Wheel Defect Prevention Research Consortium (WDPRC) to quantify the amount of expected variation in brake shoe coefficient of friction (COF) and resulting wheel temperature throughout the life of an individual brake shoe. Variations in brake shoe COF within an individual railcar are one potential source of elevated wheel temperatures and thermal mechanical shelling (TMS) damage to the wheels. High friction composition and tread conditioning brake shoes were installed in the “as manufactured” condition with no wear-in or machining at the beginning of the test matrix which consisted of seventeen stop tests and twelve grade tests. For each brake shoe tested, the average COF and maximum wheel temperature were recorded during eleven identical light grade tests interspersed throughout the test matrix.


2010 ◽  
Vol 2 (2) ◽  
pp. 8
Author(s):  
Evy Setiawati

Rattan on frequently attacked by the powder post beetle (Tellu, 2001). The prevention of dry powder attacks is done by preservation. The increasing resistant of rattan from insect attack can be done by an environmentally friendly preservative, the Galam wood vinegar. This research  aims to determine the most effective concentration of preservative that shows the lowest attacks level of D. Farb minutus powder. The rattan used is green rattan (Calamus sp.) The concentration of preservative that are used:10%, 40%, 70% and 100%. The testing of dry powder attack  used force feedback method. The effectiveness test parameters of wood vinegar to dry powder attacks  included degree of protection Dinoderus minutus Farb. powder,  reduction percentage of rattan weight and the mortality of dry powder Dinoderus sp for toxicological testing of wood vinegar. The test results showed that the degree of protection powder in rattan growing along with the increased concentration of preservatives. The higher the concentration of  wood vinegar, the smaller the reduction of rattan weight and the higher the mortality rate of dry powder. Keywords: resistant of rattan, wood vinegar, Dinoderus minutus.


Author(s):  
J. Shi

Scatter in test results is common for relatively brittle materials such as ceramic matrix composites. The scatter may come from differences in material processing conditions, specimen machining/handling and from variations in test parameters for nominally the same test material. Large scatter in test results makes material modeling difficult. In the past, master curve concepts have been proposed to reduce scatter in tensile data and to interpret fatigue/creep results. In this paper, one such concept is examined in detail by applying it to the recent tensile test results of a SiC/SiC composite. It was found that the way to construct master curves did not apply to the CMC studied and thus a new master curve was developed to better represent the tensile data. In addition, the test data were analysed statistically based on the new master curve.


2021 ◽  
Vol 5 (2) ◽  
pp. 1
Author(s):  
Ety Jumiati ◽  
Ufik Eliati Tumanggor ◽  
Abdul Halim Daulay

<p align="center"><strong><em>Abstract</em></strong></p><p>Ceiling evelopment by utilizing waste corn cobs, coconut coir with gypsum flour an the adition of latex adhesive. Variations in the composition of the mixture of corn cobs, coconut coir, gypsum flour with latex adhesive include sample A (0:0:100:15), sample B (3:3:94:15), sample C (6:6:88:15), sample D (9:9:82:15), sample E (12:12:76:15), and sample F (15:15:70:15) with emphasis using a <em>hot press </em>and drying for 28 days. The test parameters include flexural strength and fracture strength. The test results show that sample B in the composition (3:3:94:15) is the optimal result. In this composition, the resulting ceiling board has the characteristics of a flexural strength of 3966,39 kgf/cm<sup>2</sup> and a fracture strength of 1088,6 kgf/cm<sup>2</sup>.</p><p><strong><em>Keyword :</em></strong><em> Lateks , Ceiling Board, Coconut Coir, Corn Cob</em></p><p><em> </em></p>


2010 ◽  
Vol 163-167 ◽  
pp. 3297-3300 ◽  
Author(s):  
Jia Wei Shi ◽  
Hong Zhu ◽  
Zhi Shen Wu ◽  
Gang Wu

Coupon tests were conducted to investigate the mechanical characteristics of basalt FRP (BFRP) sheet, basalt-carbon hybrid FRP sheets and the corresponding epoxy rein under the effect of freeze-thaw cycling. FRP sheets and epoxy rein coupons were subjected to up to 200 and 250 freeze-thaw cycles respectively. Test parameters included the number of freeze-thaw cycles and the types of FRP composites. Test results show that (1) BFRP sheet perform better than CFRP or GFRP sheets under high freeze-thaw cycles; (2) exposed hybrid FRP sheets not only show very little loss in mechanical properties, but also contribute to the stability of test data; (3) mechanical properties of rein epoxy decrease significantly with increasing freeze-thaw cycles.


2021 ◽  
Vol 87 (12) ◽  
pp. 36-41
Author(s):  
A. S. Fedorov ◽  
E. L. Alekseeva ◽  
A. A. Alkhimenko ◽  
N. O. Shaposhnikov ◽  
M. A. Kovalev

Carbon dioxide (CO2) corrosion is one of the most dangerous types of destruction of metal products in the oil and gas industry. The field steel pipelines and tubing run the highest risk. Laboratory tests are carried out to assess the resistance of steels to carbon dioxide corrosion. However, unified requirements for certain test parameters are currently absent in the regulatory documentation. We present the results of studying the effect of the parameters of laboratory tests on the assessment of the resistance of steels to CO2 corrosion. It is shown that change in the parameters of CO2 concentration, chemical composition of the water/brine system, the buffer properties and pH, the roughness of the sample surface, etc., even in the framework of the same laboratory technique, can lead in different test results. The main contribution to the repeatability and reproducibility of test results is made by the concentration of CO2, pH of the water/brine system, and surface roughness of the samples. The results obtained can be used in developing recommendations for the choice of test parameters to ensure a satisfactory convergence of the results gained in different laboratories, as well as in elaborating of a unified method for assessing the resistance of steels to carbon dioxide corrosion.


1966 ◽  
Vol 88 (4) ◽  
pp. 352-357 ◽  
Author(s):  
Malcolm S. Riegel ◽  
Samuel Levy ◽  
John A. Sliter

Two computer analyses have been prepared relating service stresses in railroad wheels to wheel shape and dimensions. One program computes the temperature distribution and stresses due to heat input by brake shoe friction at the wheel tread. The other computes stresses due to lateral, vertical, and tractional forces between the wheel and rail. Both programs have been validated for certain known conditions using theoretical solutions and are in agreement with available design and experimental stress data to the degree that differences in wheel geometry and loading conditions permit a comparison with experimental stress data. The next step contemplated is better experimental confirmation by computations for specific wheels and loadings for which test results are available and use of the programs to study trends resulting from, changes in wheel geometry and dimensions. This work is directed toward optimization of wheel design, and elucidation of the nature and specific effects of excessive service loads. This research program is being sponsored at General Electric by the manufacturers of wrought steel wheels, through the American Iron and Steel Institute, as a service to the American railroad industry.


Proceedings ◽  
2018 ◽  
Vol 2 (8) ◽  
pp. 461 ◽  
Author(s):  
Etienne Harkemanne ◽  
Olivier Berten ◽  
Patrick Hendrick

In an aircraft engine, some pieces are describing a rotating movement. These parts are in contact with rotating and non-rotating parts through the bearings and gears. The different contact patches are lubricated with oil. During the lifetime of the engine, mechanical wear is produced between the contacts. This wear of the bearings and gears will produce some debris in the oil circuit of the engine. To ensure the effective operation of the aircraft engines, the debris monitoring sensors play a significant role. They detect and collect the debris in the oil. The analysis of the debris can give an indication of the overall health of the engine. The aim of the paper is to develop, design and model an oil test bench to simulate the oil lubrication circuit of an aircraft engine to test two different debris monitoring sensors. The methodology consists of studying the oil lubrication system of the aircraft engine. The first step is to build the oil test bench. Once the oil test bench is functional, tests are performed on the two debris monitoring sensors. A test plan is followed, three sizes of debris, like the type and sizes of debris found in the aircraft engine oil, are injected in the oil. The test parameters are the oil temperature, the oil flow rate and the mass of debris injected. Each time debris is injected, it is detected and caught by the two sensors. The test results given by the two sensors are similar to the mass debris injected into the oil circuit. The two sensors never detect the total mass of debris injected in the oil. On average, 55%–60% of the mass injected is detected and caught by the two sensors. The sensors are very efficient at detecting debris whose size corresponds to the design range parameters of the sensors, but the efficiency falls when detecting debris whose size lies outside this range.


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