FRACTURE-TOUGHNESS EVALUATION

Fracture toughness evaluation techniques are well established for meta llic materials and standard test procedures are available for the dete rmination of linear elastic (K-IC or K-C) or elastic-plastic (J(IC) or delta) fracture toughness parameters. Although several test technique s have been developed for the evaluation of fracture toughness of stru ctural ceramics, unlike metals, no standard procedures are available a s yet. On the other hand, mixed mode fracture is an emerging area and test methods have been proposed only recently.