Investigation of the C-ring test for measuring hoop tensile strength of nuclear grade ceramic composites

•Hoop strength of nuclear grade silicon carbide tubular composites was measured.•Increased strength and toughness was observed for the composites versus monolithic.•Expanding plug and C-ring testing agree to 6% for samples tested.•Despite limitations, for some samples C-ring can give accurate hoop strengths.•C-ring is useful for quality control, material R&D, when material is at a premium. Silicon carbide (SiC) and silicon carbide fiber reinforced composites (SiC/SiCf) are currently being evaluated as a high temperature material for use in nuclear reactors. While methods to determine the mechanical properties of SiC/SiCf on planar test specimens are well established, mechanical testing methods for tubular SiC/SiCf are still being developed. In this study the C-ring test is evaluated for use with nuclear grade SiC/SiCf as a method of measuring hoop strength. For the samples tested in this work, hoop strengths from C-ring testing are shown to agree within 6% to those obtained using expanding plug testing and analysis shows that the expected composite behavior is observed during testing. While other techniques may give more accurate values for hoop stress, the small specimen requirements and ease of testing makes C-ring testing a valuable tool.