Mechanical properties and failure mechanisms of all-CFRP corrugated sandwich truncated cone.

Cone-shaped sandwich structures are extensively employed in various fields due to their excellent bearing efficiency and designability. In this work, the design approach and integrated manufacturing method for the carbon fiber reinforced plastic (CFRP) corrugated sandwich truncated cone (CSTC) are proposed to improve the anti-debonding ability and ensure the reliability of the sandwich cone. First, the theoretical model for the stiffness of the CSTC is derived, in which the conservative prediction and the upper limit considering the fiber orientation of the cone are derived. The multiple failure modes of the CSTC under axial compression are theoretically established. Then, the failure mechanism map of the CSTC is established to forecast the possible failure modes. The typical failure modes of local buckling, face fracture, and core buckling are captured by experiments and finite element analysis (FEA). The theoretical model of the stiffness and failure modes is verified by the experiments and FEA. The effect of the semi-vertex angle and circumferential cell number on the failure modes is revealed. Furthermore, a more comprehensive failure mechanism map is generated by altering the geometric parameters of the CSTC. The failure modes of Euler buckling and global buckling are acquired by the comprehensive failure mechanism map and verified by FEA. Finally, the optimum design of the CSTC structure is performed. The results show that the failure mode of face fracture has the best bearing efficiency. This research provides a solid foundation for designing and applying lightweight CSTCs in constructions, such as the adapter of launch vehicles. [Display omitted] • The structure design method and integrated preparation technology of CFRP corrugated sandwich truncated cone are proposed. • The theoretical models of the stiffness and failure modes of the CSTC under axial compression are derived and verified. • The conical sandwich structure is more prone to global buckling with the increase of the semi-vertex angle. • It is found that the failure mode of face crushing has the highest bearing efficiency in structural optimal design. [ABSTRACT FROM AUTHOR]