Date of Publication:  March 1993

Sponsoring Agency:  U.S. Department of Transportation, Federal Railroad Administration, Office of Research and Development

Performing Organization:  Association of American Railroads, Transportation Test Center, Pueblo, Colorado

Report No: DOT/FRA/ORD-93/10

Abstract:

Under the Tank Car Fatigue Crack Growth Test program, the Association of American Railroads performed over-the-road tests, impact tests, perturbed track tests, quasi-static and cyclic Mini-shaker Unit vertical coupler loading tests, and a 300,000-mile accelerated-rate Simuloader fatigue test on a Department of Transportation 111A100W1 tank car. In addition, fractographic analysis of cracked tank car head pad samples obtained in the field and laboratory specimen crack growth tests were conducted.

It was determined that the critical region in fatigue of the tank car tested was the stub sill to tank-head reinforcing pad connection. The following conclusions were drawn during the course of the test program.
 

• The predominant factor in the cracking at the stub sill to tank shell connection was the vertical coupler loads.
• The Simuloader was able to re-create realistic load environment. One hour of Simuloader operation corresponded to 4,400 miles of revenue service.
• It was possible to monitor crack growth during the Simuloader testing of the tank car. The propagation of seven fatigue cracks was monitored.
• The fatigue load environment can be applied to any tank car on TTC’s Simuloader, therefore allowing new stubsill designs to be tested.

No. of Pages:  178