Promoting Progressive Crushing in Thin-Walled CFRP Tubes for Aircraft Absorbing Structures: An Experimental Study

In this paper, an architecture-based approach is proposed to enhance the quasi-static crushing behaviour of trigger-free composite energy-absorbing structures. To validate the proposed methodology, specimens with an inner diameter of 32 mm and a wall thickness of ~ 1 mm were manufactured and tested under axial quasi-static compression (20 mm/min) using a filament winding technique. Two sets of samples were fabricated by including an external CFRP mesh to enhance the hoop strength and promote progressive crushing. By comparing the test results with those of the base material, a remarkable influence of the outer layer on the crash performance (> 50% of the SEA) was registered, despite a negligible increase in weight. Furthermore, since geometric modifications (e.g., edge chamfering) were unnecessary to achieve progressive crushing because of the contribution of the outer mesh, this approach can be further explored to simplify the manufacturing process of energy-absorbing structures.