Bar Impact Tester for Dynamic Fracture Testing of Ceramics and Ceramic Composites

摘要

A bar impact test was developed to study the dynamic fracture responses ofprecracked ceramic bars, Al2O3 and 15/29% volume SiCw/Al2O3. Laser interferometric displacement gage data was used together with dynamic finite element analysis to determine the instantaneous crack length and the dynamic stress intensity factor, K sub ID(t), in the fracturing ceramic bars impacted with impactor velocities of 5.8, 8.0, and 10 m/s. The crack velocities increased from 1400 to 2600 m/s with increasing impact velocity. K sub ID(t) initiated at the expected dynamic fracture toughness and increased with time and with increasing impact velocity. The dynamic initiation fracture toughness and an increasing K sub ID(t) with time and increasing impact velocity were obtained.