The splitting test method on dynamic tensile strength of Al 2 O 3 ceramic material

Abstract

The splitting tensile test is an acceptable method for determining tensile strength at quasi-static strain rate. In the present paper, the experimental method on the dynamic splitting tensile test of ceramic is introduced based on the Split Hopkinson Pressure Bar (SHPB) test technique. In order to demonstrate the dynamic stress distribution in high strain rate splitting tensile test, the numerical simulation on the dynamic splitting tensile test of Al₂O₃ ceramic is carried out by using the FEM code LS-DYNA. The numerical simulation gives the stress distributions in the Al₂O₃ ceramic specimen under different loading cases. It is shown that the dynamic stress distributions are similar to that in the static situation. And the suitability of dynamic splitting tensile test for ceramic is verified. It can be seen that the high tensile stress area initiates firstly near the impact end of the specimen and spreads to the other end of the cylinder. In the numerical simulation the tensile stress that directly obtained in the specimen is compared with that obtained by the transmitted stress, and it can be seen that they are almost the same. This verifies the validity of dynamic splitting tensile test by using SHPB. Finally, it is can be concluded from the numerical simulation that the stress level and the rise time of pulse are the most important factors that affect the strain rate under different loading case.