Thermal Shock Behavior Analysis of SiC Composite Cladding

In order to solve the problems of poor convergence and insufficient research on thermal shock performance in the simulation of thermal shock behavior of SiC composite cladding, this paper simulates the internal stress state of double-layer SiC composite cladding under Loss of Coolant Accident (LOCA), uses the COMSOL software of multi-physical field coupling to numerically simulate the thermal shock behavior of SiC composite cladding, and analyzes the effects of thickness ratio, thermal shock temperature and end plug on the thermal shock resistance of SiC composite cladding. The results show that the circumferential stress produced by thermal shock increases with the increase of the thickness ratio of chemical vapor infiltration layer (CVI layer) to chemical vapor deposition layer (CVD layer); When the thickness ratio of CVI layer to CVD layer is 9:1, the circumferential tensile stress of SiC composite cladding during thermal shock can reach 113 MPa; The circumferential stress produced by thermal shock increases with the increase of thermal shock temperature difference. When the thermal shock temperature is 1200 K, the circumferential stress is 112.7 MPa; During thermal shock, there is obvious stress concentration at the end plug, and its radial stress is up to 22.3 MPa, which is higher than the bonding strength reported in the literature (20~25 MPa), which is the main reason for the failure of the end plug connection.