UNDERSTANDING THE INFLUENCE OF MANUFACTURING DEFECTS ON THE TENSILE BEHAVIOR OF SIC/SIC FILAMENT WOUND TUBES FROM A UNIDIRECTIONAL COMPOSITE MODEL

SiC/SiC ceramic matrix composites are promising cladding candidates to improve the accident tolerance of the fuel in pressurized water reactors. Indeed, their excellent mechanical properties at high temperatures (above 1200°C) would give them additional margins to face a loss of coolant. In this work, the mechanical behavior of a filament wound tube under cyclic tensile stress is performed in order to investigate the impact of two types of manufacturing defects on the mechanical behavior. The defects studied correspond to local modifications of the composite microstructure. For both classes of defects, the same methodology is used, consisting in performing mechanical cyclic tensile tests in the tube axis direction with post-analysis to assess fine parameters. The results allow characterizing the elastic behavior, as well as, the behavior during matrix microcracking through the consideration of unload-reload cycles. Microstructiral analyses are performed to establish the mechanical properties/microstructures relationship.