Thin walled circular beams with sinusoidal embedded patterns under axial impacts

• Performance of patterned tubes as crash absorbers under axial impact is studied.
• CBC patterns are developed by multiplying radial and longitudinal frequency
• Effect of varying radial lobes, amplitude and longitudinal frequency is studied.
• Effect of varying amplitude of radial frequency on SEA is significant.
• Longitudinal geometrical frequency had a marginal influence of energy absorption characteristics.

Several recent developments have shown that introducing sinusoidal patterns on square section automotive crash absorber beams increased the energy absorption. This paper studies the behaviour of patterned circular tubes when used as crash absorbers. The effect of varying parameters of radial and longitudinal geometrical pattern frequency on internal energy absorption and energy absorption effectiveness factor is also studied in this work. Different types of patterns were simulated in axial impacts in which two geometrical pattern frequencies (radial and longitudinal) are multiplied. A numerical investigation was carried out using the commercially available LS-DYNA™ solver. The investigation was verified using existing analytical models. Results indicate that the circular sinusoidal patterned tubes behave better in energy absorption in axial impact. However, circular tubes have an altogether different collapse mode therefore the pattern formation has to be modified and optimized differently as compared to square beams. A new set of patterns named as CBC patterns is proposed in the study which increased the energy absorption of circular tubes significantly. An increase of about 36.86% in energy absorption is noted and energy absorbing efficiency factor is escalated from 2.23 to 3.05 in the best case. This research may further endorse the feasibility of using sinusoidal patterned tubes in mainstream engineering applications.