Reducing initial peak force through chamfered triggers: A study on thin-walled tubular structures for energy absorption and crash protection

Thin-walled tubular structures play a significant role in energy absorption owing to their lightweight nature, low cost, and high specific energy absorption, which are widely applied in crash resistance in aerospace and vehicle fields. However, the structures always denote a high initial peak force; thus, triggers have attracted tremendous attention. In this study, a chamfer trigger has been presented to decrease the peak crushing force, and a thin-walled structure has been designed to absorb energy. First, the proposed trigger has been verified by finite element analysis. Then, a square conical thin-walled multi-cell structure is designed and analyzed by experimental tests and finite element analysis. Moreover, the parametric analysis and multi-objective optimization design have been applied to figure out the influences of structural parameters on the energy-absorbing performance. Finally, a horizontal crash test has been carried out to verify the availability of the designed structure. The chamfer trigger proposed can be used in thin-walled tubular structures to decrease the initial peak force, and the designed structure can be utilized in high-speed helicopter and automotive fields.