Dynamic Creep Behaviors of Si-Ti-C-O Ceramic Fiber Bonded Body under Bend Loading at Elevated Temperature

Abstract

Dynamic creep test and its analysis were performed for Si-Ti-C-O ceramic fiber bonded body under bend loading at 1400°C. Creep displacement under cyclic loading with mean stress σ_m1=196MPa and stress amplitude σ_a=49MPa is quite similar to the one under constant static load of σ₀=196MPa, while the dynamic creep displacement under loading condition at σ_m1=245MPa and σ_a=49MPa is much larger than static creep displacement at σ₀=245MPa. SEM observations revealed that the failure of matrix material was caused around the neutral plane of the specimen by cyclic shear stressing in the dynamic creep process at σ_m1=245MPa and σ_a=49MPa. Finite element method analysis was performed for the dynamic creep process, where the gradual attenuation of shear modulus G₁₂ with progress of dynamic creep was assumed. The calculation described qualitatively well the dynamic creep deformation behavior of this material. The normal stress distribution of the specimen and the shear stress distribution in the neutral plane along the specimen axis were presented on the basis of the FEM calculation.