cross section crash boxes

were constrained. Since the width of the welding zone was measured 9 mm, the
rotational motions of all nodes in a distance 6 mm from the top and bottom of tube were
not allowed in all direction (Figure 5.4(b)). The translation motion of weld zone nodes
was only allowed in Z direction. Similar constraints were also previously applied in
the simulation of the crushing of 5018 Al tubes (Williams, et al. 2007).
(a) (b)
Figure 5.4. The model of a) crash box without montage plates and b) crash box with
montage plates.
The self contact of crush zone surfaces (contact between folds) was modeled
with automatic single surface contact algorithm (Figure 5.5(a)). Automatic surface to
surface contact algorithm was used to simulate the contact between foam filler and box
wall and box edge and weld plates of crush boxes with montage plates (Figure 5.5(b)).
The contact between crash zone and montage plates was modeled with automatic nodes
to surface contact algorithm. Lastly, the static and dynamic friction coefficients were
taken 0.3 and 0.2, respectively.
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