Fracture toughness testing: Impact of the precracking requirements on economical considerations

Precracking is an essential item in sample preparation for fracture toughness testing. On one hand, one wants to precrack at the lowest possible load to ensure that precracking won't affect the test results. On the other hand, one wants to carry out precracking in an economical way by reducing the time to precrack. This report aims at investigating the two different economical aspects of precracking, i.e., the cost for the equipment and the time needed to precrack one specimen. The duration is indeed an important parameter as it immobilizes costly equipment and personnel. It is found that, from an economical point of view, requiring to precracking at K values lower than 16MPa„©m is not acceptable.