“…Abramowicz [29,31,32,33,34], D. Kecman [30], and T. Wierzbicki [31,32,33,34] apply different ways of deriving the mathematical equations that accurately predict the bending resistance of the box section beams. In some of the simplified crash models developed previously in the literatures [24,27] and in chapter 2, these equations define the nonlinear spring elements, which s.imulate the crash behavior of the plastic hinges during a crash.…”