cross section crash boxes

experimental tensile stress-strain curves are shown together in Figure 7.3(b). Both
models, as seen in Figure 7.3(b), adequately capture the elastic and plastic deformation
regions of the experimental tensile stress-strain curve of 1050 H14 Al base material.
The models cannot however correctly predict the stress values of the base material in
the regions following the ultimate tensile strength, depicted in Figure 7.3(b). A ductile
failure mode with the well known necking phenomenon is seen in the experimentally
tested samples (Figure 7.3(a)). The shear plane cracking observed in experimental
tensile test is however not observed in the simulations with both material models
(Figure 7.3(a)). A similar observation was previously reported in the tensile testing
simulation of a similar Al alloy (Lademo, et al. 2008). The deformation of crash boxes
was however simulated in this thesis using Mat 3 card, as Mat 3 card uses shorter
calculation times than Mat 24 card.
(a)
Figure 7.3. The deformation pictures of numerically tensile testes sample and fractured
experimental tensile test sample and (b) experimental and numerical, Mat 3
and Mat 24, engineering stress–strain curves of 1050 H14 Al.
(cont. on next page)
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