Abstract
Although viscoelastic materials are widely used in the recent industrial fields, investigation on criteria for onset and subsequent crack growth in those materials from a viewpoint of continuum mechanics, has not been so active in comparison with those in case of elasto-plastic metallic materials. As one of the reasons for this situation, it is pointed out that difficulties in theoretical and experimental analyses of such kinds of solids and sheets are mainly caused by dependence of viscoelastic mechanical behaviors on loading history in addition to those merely on temperature and loading rate.
In this paper, the author would like to explain fundamental treatments of fracture problem in viscoelastic materials based on criterion for onset and subsequent crack growth, which are classified into the following five categories, such as,
(1) the global energy balance criterion,
(2) the local energy balance criterion,
(3) the COD criterion,
(4) the displacement field criterion.
(5) the criterion based on the conservation law.
