Modeling Material Failure During Cab Car End Frame Impact

New standards have been proposed to increase the strength requirements for cab car end structures and impose further requirements on their ability to absorb energy during a grade-crossing collision. This conference paper reports on a set of full-scales tests completed by Federal Railroad Administration (FRA) and the Volpe Center to assess the quasi-static and dynamic crush behavior of these end structures. In support of this testing program, end frames designed to meet the new standards were fabricated and retrofitted onto the forward end of an existing cab car. A series of large-deformation quasi-static and explicit dynamic finite element analyses (FEAs) were performed to evaluate the performance of the design. A material failure model, based on the Bao-Wierzbicki fracture criterion [3], was implemented in the FEA model of the cab car end frame using ABAQUS/Explicit. The FEA model with material failure was used to assess the effect of fracture on the deformation behavior of cab car end structures during quasi-static loading and dynamic impact and, in particular, the ability of such structures to absorb energy. Model parameters were validated and material strength and failure parameters were derived for A710 steel. The model was then used to simulate the three full-scale tests that were conducted during 2008 as part of the FRA program: a collision post impact, and quasi-static loading of both a collision post and a corner post. The researchers found need for revisions to both the design of some key end frame components and to key material failure parameters. Using the revised model, pre-test predictions for the outcome of the corner post test were found to be in very good agreement with test results.

Language

  • English

Media Info

  • Media Type: Print
  • Features: Figures; Photos; References;
  • Pagination: 10p

Subject/Index Terms

Filing Info

  • Accession Number: 01147249
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 15 2009 10:31AM