Damage

Abstract

In Chapter 1 of Volume I we surveyed the various ways in which materials can be deformed, and the corresponding constitutive equations; this enabled us to calculate the deformations and stresses experienced by a sample subjected to external loads of various types. The question now arises of determining the limits that must not be exceeded if the material is not to suffer damage to its structure, possibly leading to rupture. If we are considering a volume of the material that is large compared to the size of the damage, the latter must be integrated into the behaviour law; and for a rigourous treatment the coupling between the mechanisms of deformation and rupture must be taken into account. If the microfissures, the microcavities resulting from the growth or the coalescence of defects, are large enough this approach to the problem is no longer valid; recourse must then be had to fracture mechanics, which is the subject of the next chapter.