Static and dynamic shear testing of ceramic materials

Ceramic materials are characterized by unique combinations of properties that make them attractive for many specialized applications where metals are inadequate. On the other hand, their inherent brittleness makes the design and development of reliable ceramic structural members extremely difficult. In order to obtain engineering data to be introduced in computer codes, the following developments are presented: (i) A special specimen which permits the ceramic material to be subjected in one–dimensional shear or combined shear by loading it in compression (or tension) and torsion; (ii) A classical hydropneumatic press, capable of applying compressive loads and introducing one–dimensional shear on the specimen, at low strain rate (quasi–static); (iii) A new device (pressure–bar), based on the stress–wave technique, capable of applying on the new ceramic shear specimen, axial compression and torsion and subjecting it to one–dimensional or combined shear. This device operates in the field of strain rates up to 10³ s−1. First results obtained by testing the new ceramic shear specimen of A12O3 (92%) on the hydropneumatic press are reported.