Compression responses of composite corrugated sandwich square tube: Experimental and numerical investigation

By means of re-bonding inner square tube, corrugated core and outer square tube produced by hot pressing molding method, the composite corrugated sandwich square tubes (CCSSTs) were manufactured. Axial and lateral compression experiments were carried out on CCSSTs with length of 50 mm and 25 mm respectively, and the mechanical responses such as load, displacement and mid-height strain during the loading process were measured. The composite progressive damage finite element models were used to simulate the compression failure processes of CCSSTs. The simulated failure modes and load-displacement curves were in good agreement with experimental results. An analytical model based on homogenization theory was provided to evaluate the regularity of axial and lateral compression stiffnesses of CCSSTs. The research showed that the CCSST mainly underwent face crushing, face debonding and local buckling under axial compression. The lateral compression bearing capacity of CCSST reduced mainly caused by the outer face debonding. Increasing the height of the core could improve the axial compression stiffness and specific axial compression stiffness. The lateral compression stiffness performance and light weight benefit were both satisfying when the corrugation angle reaches 90 degrees.