Freight Car Fatigue - Coal Car Simulator Demonstration Test

A full scale fatigue test of a 100-ton coal gondola car on the Transportation Test Center's (TTC's) Simuloader facility was successfully completed recently. With a short test encompassing 270 hours of Simuloader testing, the freight car was subjected to fatigue damage equivalent to 600,000 miles of revenue service. The test car developed fatigue cracks at locations where similar cracks had been experienced earlier in revenue service. An over-the-road test was run to collect data required to "drive" the Simuloader and to characterize the structural and dynamic response of the coal car in revenue service. The road test route information was then "condensed" by selecting, from the 120 hours time history, events which were fatigue significant, that is, when the freight car experienced high loads and stresses at critical locations. The uneventful miles were edited out. The 2,200 miles road test route of 120 hours travel time was condensed to the Simuloader test load cycle of only one hour. So, during the Simuloader test the car was subjected only to the high loads which may cause fatigue damage to the car structure. The author observed during the Simuloader tests that the car body dynamic response at critical strain gage locations was quite similar to what was observed in the road test. It was also established that, for accurate simulation of coupler loads, it is important to remove as much slack as possible from the draft gear pocket. Also, the gains of the Simuloader actuators can be increased as needed to further accelerate the fatigue test.

• Record URL:
  • https://www.fra.dot.gov/eLib/details/L18003#p1_z25_gD_lRT_y1990
• 
• Corporate Authors:

  Association of American Railroads Technical Center

  3140 South Federal Street
  Chicago, IL  United States  60616

  Federal Railroad Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Sharma, V
• Publication Date: 1990-12

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Research Report
• Features: Appendices; Figures; Photos;
• Pagination: 154p

Subject/Index Terms

• TRT Terms: Fatigue cracking; Fatigue tests; Freight cars; Gondola cars; Railroad simulators
• Subject Areas: Railroads; Vehicles and Equipment;

Filing Info

• Accession Number: 01666275
• Record Type: Publication
• Report/Paper Numbers: R-747
• Contract Numbers: DTFR53-86-C-00011
• Files: TRIS, ATRI, USDOT
• Created Date: Apr 18 2018 5:06PM