b'together with strain (via traditionalconducted several test campaignsFigure 1. Failure envelope of tri-axial resistance foil gage and digital imageon these representative materialsbraid SiCf-SiCm composite tube correlation) and acoustic emissionand obtained failure multiaxialextracted from a large number of combined loading tests. (UTS, ultimate from the samples. X-ray computedfailure envelope as shown in Figuretensile strength; PLS, proportional tomography was utilized to observe1. The failure envelope revealslimit stress.)samples after tests. GA fabricatedstrong direction-dependence of the SiCf-SiCm tubes for this projectmechanical strength. For tri-axial using standard GA-Electromagneticbread composite tube, axial direction Systems Group procedures used forturns out the strongest direction due the Department of EnergyNuclearto the set of axial tows in addition to Energy Accident Tolerant Fuelthe two sets of bias tows. The hoop Program. This includes a thin pyro- direction is the 2nd strongest direc-lytic interphase coating depositedtion. Surprisingly, a much weaker directly on the fibers and a crystal- direction is revealed when the 1st line SiC matrix deposited usingprincipal direction is at 45 degrees chemical vapor infiltration. UofSCwith respect to the hoop direction.2022|AFC ACCOMPLISHMENTS 71'