Interlaminar shear strength of a unidirectional fiber-reinforced celsian composite by short-beam and double-notched shear tests

Interlaminar shear strengths of a unidirectional Hi-Nicalon-(BaSr)Al2Si2O8 celsian composite were measured by both the short-beam shear and double-notch shear test methods between room temperature and 1200degreesC. Test results clearly indicated that the shear strength depends on the test method used. At low temperatures the strength values by the short-beam shear test were about 60% higher than those by the double-notch shear test. At high temperatures, however, the shear strength by both test methods dropped sharply due to the viscous flow of the residual amorphous phase in the composite and the values converged. The comparison of stress distribution in both test specimens suggests that the high stress concentration associated with the notches was responsible for the low strength values by the double-notch test method.