Proportional limit stress and residual thermal stress of 3D SiC/SiC composite

Proportional limit stress (PLS) and residual thermal stresses (RTS) of 3D SiC/SiC composite were investigated. PLS was obtained by four different methods from the monotonic stress-strain response curve to get a convincing value. RTS in the SiC matrix was quantified by solving the geometric intersection point of the regression lines of hysteresis loops from the periodical loading-unloading-reloading cycle test curve. Classical ACK model and analytical formulas were used to analytically calculate the PLS and RTS of 3D SiC/SiC composite. Good agreement between the experimental results and the analytical calculation was observed. And relationship between the PLS and the RTS of 3D SiC/SiC was discussed.