cross section crash boxes

Figure 3.27. SEA values of empty and foam filled single, double and triplecell square
Al sections (Source: Chen and Wierzbicki 2001)
Jones defined an energy-absorbing effectiveness factor which was based on the
material properties, the cross-section of the structure, stiffeners and foam filling,(Jones
In Press). Using the experimental data from literature, the energy-absorbing
effectiveness factor of a 6060T4 Al tube was shown to increase with foam filler density
(Figure 3.28)
The axial crushing behavior empty and foam filled square hat sections (Figure
3.29(a)) was investigated under static and dynamic loads (Altenhof, et al. 2002, Chen
and Nardhi 2000, Wang, et al. 2005, Wood, et al. 2006). The SEA values of single hat
filled section were higher than those of empty single hat section. While, in double hat
sections, a critical filler length after which filled section became more efficient than
empty section was found (Figure 3.29(b)).
The crushing behavior of empty and foam filled single, double hat HS5754 Al
sections with and without center plate were determined by Chen et al. (Chen and Nardhi
2000). Several different foam filling methods including precise fitting, precompression
fitting and adhesive bonding were investigated to find out the best filling method that
stabilized the deformation and maximized SEA. Adhesive bonding was shown to cause
less premature joint failure than precise fitting and precompression fitting. Finally, foam
filled single and double hat steel square columns were shown to exhibit 20% higher
SEA values than empty single and double hat columns.
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