Multi-failure theory of composite orthogrid sandwich cylinder

Under uniaxial compression, carbon fiber reinforced composite (CFRC) orthogrid sandwich cylinder has four potential failure modes, including global buckling, monocell buckling, rib buckling and material failure. The smearing method was applied to predict the equivalent stiffness and calculate the stresses of the skins and the orthogrid, providing fundaments to build the failure criteria. Theoretical models were established to reveal the failure modes and predict the ultimate load of the compressed orthogrid cylinder by the way of failure maps, providing a feasible way to optimally design CFRC anisogrid cylinder.