Delayed under general loading conditions

Delayed Fracture under General Loading Conditions... 

Unlike the shear yield process, crazing is an inherently non-isovolume event. Cavitation of the material requires a dilatational component of the stress tensor, such as occurs in triaxial stress systems that may be foimd in samples subjected to plane strain conditions. In addition, it is foimd in practice that there is a time dependency on the appearance of crazing. That is, there is generally a time delay between application of the load and the first visible appearance of a craze. A number of models have been proposed which require either a critical cavitation stress, a critical strain, or the presence of inherent microvoids, which can grow under the applied local stress or strain. 

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