Inelastic Analysis of Notched Components in Silicon Nitride Ceramics at Elevated Temperature

Abstract

The displacement rate-controlled tensile tests were performed for smooth and circumferentially notched specimens of the sintered silicon nitride ceramics in argon-gas atmosphere at 1300°C, and then the axial load-displacement response was measured. It was shown from the tests that inelastic deformation was greatly dependent on displacement rate and easier to generate at the lower displacement rate. The constitutive equation was constructed on the basis of tensile stress-strain curves in the smooth specimen. Then inelastic FEM analysis was performed for the smooth and notched specimens, using this equation. The calculated load-displacement responses quantitatively agreed quite well with the measured ones in the smooth and notched specimens, showing the validity of the proposed analysis. The development of the inelastic deformation in loading process was shown from the calculation around the notch root.