Critical Appraisal of Limiting Strain Rates for Testing Ceramics in a Split Hopkinson Pressure Bar
The split Hopkinson pressure bar (SHPB) is being widely used to determine the dynamic compressive strength of ceramics and ceramic composites. However, extreme caution needs to be exercised while testing these highstrength ceramics at high strain rates. The highest strain rate at which ceramics can be tested using an SHPB without violating the underlying assumptions is found to be in the range of 2500–3000/s. It is also shown that at very high loading rates, dispersion in the transmitted pulse can lead to discrepancies in measuring the dynamic failure strength of ceramics.
© 1994 The American Ceramic Society. Manuscript No. 194694. Received April 12, 1993; approved August 30, 1993. Supported by the National Science Foundation through a Presidential Young Investigator Award to G. Ravichandran and matching funds by the Dow Chemical Co. We would like to thank Drs. Michael El-Raheb, Yeong-Joo Lee, and Kwanho Yang of the Dow Chemical Co., Midland, MI, for helpful discussions. It is a pleasure to acknowledge the assistance provided by Mr. Weinong Chen during the course of this investigation. We would also like to thank an anonymous reviewer for helpful comments.