A Study on the Compressive Performance of C/SiC Lattice Sandwich Panel at High Temperature

In this study, the mechanical properties and failure behaviors of a C/SiC lattice sandwich panel were investigated by numerical simulation approach. On the bases of Hashin's criteria, a novel failure criterion for 2D C/SiC textile composite was proposed. An UMAT subroutine based on Abaqus code was constructed to demonstrate the fracture mechanism of the C/SiC composite, in which fiber fracture and buckling, matrix failure and the laminate delamination were considered. Out-of-plane compressive experiments of the C/SiC lattice sandwich panels at room temperature were performed to give verifications of the numerical programmer. Based on the simulation method proposed, the mechanical properties and failure features of the C/SiC lattice sandwich panels at high temperatures were studied. It was found that the junction between struts and the panels of the core firstly damaged due to fiber rupture and matrix cracking. Then fiber tensile fracture and matrix cracking occurred in struts sequentially. Finally, delamination took place at junctions and struts and it trigged the collapse of the sandwich structure.