Numerical modeling of a dual crush mode welded aluminum crash structure

Abstract The two main types of crush structures that are used to absorb energy during an automotive impact are the so-called axial crush and bending collapse structures. This paper presents results from a numerical study used to assess the crash performance of dual crush mode multi-gauge tailor-welded aluminum alloy crash structures that exhibit both modes of energy absorption. The design of these structures is based on testing of mono-gauge axial crush and s-rail structures, also presented in this paper. The axial crush structures were made from straight tubes, while the bending collapse structures (s-rails) consisted of tubes with two 45° bends that create an ȁsȁ shape. Numerical models were developed from axial crush structures with thinner tube walls welded to thicker gauge s-rails to create multi-gauge dual crush mode structures. A parametric study is presented in which the effects of the thickness ratio between the axial crush and the s-rail sections of the structure are investigated. Another parametric study is presented to examine the effects of varying cross sections of the s-rail section of the structure. Simulations of mono-gauge s-rail structures were used as a basis of comparison to assess the energy absorption performance of the multi-gauge dual crush mode structures. Dual crush mode structures are shown to lower the reaction load during impact and increase the crush displacement, compared to mono-gauge s-rail structures.

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