Numerical studies on STFD-HAT sections under axial dynamic impact

• The spot-weld double-hat section with symmetrically distributed tilt flanges is introduced.
• The new section was determined to be able to obtain better collapse mode and smoother result curve.
• Tilt angle Θ, ratios of C/H, etc. are selected as variables when designing simulation test matrix.
• The new sections with reasonable designed profiles can effectively improve the bending mode, etc.

A new type of spot-weld double-hat section with symmetrically distributed tilt flanges (STFD-HAT) is introduced in this paper to improve the crushing performance, especially crushing stability. LS-DYNA code has been employed here to analyze the effect of several parameters on the collapse modes of STFD-HAT sections under axial dynamic impact loading condition. Some variables, such as tilt angle, size of core cross-section and thickness of sheet shell, have been proved to be effective in controlling the collapse mode and crushing performance of STFD-HAT sections by analysis on energy absorption and RSS of result curves. Compared with traditional double-hat sections, the STFD-HAT sections with reasonable designed profiles can effectively improve the crushing resistances and stabilities, especially, the bending mode.