Technical Reports

Small Scale Impact Simulation Tests

  • 01
  • Jan
  • 1985
AUTHOR: Federal Railroad Administration
SUBJECT: Hazardous Materials
KEYWORDS: Scale model; tank head; impact; puncture; mitigating material; low temperature; lading
ABSTRACT: In derailments and switchyard operations, tank cars frequently experience impacts that result in tank car head puncture. From a cost effective viewpoint, it is not practical to conduct many full-scale testing to verify that a particular tank car design will perform satisfactorily in all possible impact situations. Therefore, there is a need for reliable small scale testing procedures to simulate the response of tank heads in impact situations. In this study some small scale model testing was performed: (1) to assess the effectiveness of mitigating materials on increasing the tank heads puncture resistance; (2) to evaluate the effect of low temperature on the threshold puncture energy of the model tank heads; (3) to test the validity of the scaling laws adopted; (4) to study the influence of lading on the vulnerability of the model tank head in the impact situations. A number of the 1/5 and 1/10 scale model tank heads with different head protective devices were tested under different impact, lading and temperature conditions. Besides using a stainless steel head shield as a protective device, a number of other shock mitigating materials, such as aluminum honeycomb materials, aluminum foams, corrugated steel plates, and TecsPak plates, were investigated. The test results indicate that both TecsPak and stainless steel provide good protection against head puncture even at low temperatures as compared with the bare tank heads; however, no substantial difference is found in terms of protection capability between TecsPak and stainless steel plates. An examination of the threshold puncture velocities between the two scaled models showed a difference of less than 10%. This concluded that the scaling laws adopted provide good accuracy in scaling the model tank heads.