Technical Reports

Tank Car Damage Assessment Procedure Study

  • 01
  • May
  • 1984
AUTHOR: William P. Wright
SUBJECT: Facilities & Test Equipment
KEYWORDS: Safety, Nondestructive Evaluation, Fracture Mechanics
ABSTRACT: The study concerns the rupture of damaged tank cars which have been involved in railroad accidents. In this regard, a series of impact tests using the FRA/BRL Drop Hammer Facility was performed. The tests consisted of the creation of controlled damage to flat steel plates which had properties exceeding the minimum ASTM standards required for steel used in the construction of tank cars (ASTM A-515, Grade 70 steel). The plates responded in the form of dents which reflected the shapes and sizes of tups which were driven onto the plates and the sizes of dies on which the plates were placed. As expected, the shapes of the dents were similar to the shapes of the tups and as the dies were changed to larger diameters, the amount of bending increased. A total of 70 tests were conducted with various hammer heights, tup shapes and sizes, and die diameters. The maximum dent depth as a function of impacting kinetic energy was shown to be a scaling function. Several of the plates were analyzed using NDE techniques (ultrasonics and dye penetrant) and fracture mechanical procedures. Several important correlations were discovered between the dent characteristics and levels of flaw damage found in the material. The results were encouraging and a series of tasks are identified as the best approach for continuing on toward a final solution.