An abundance of comparisons with experimental evidence has long settled that the Griffith energy competition along a known crack path — commonly expressed as a criticality condition on the energy release rate — describes when a large crack grows in a nominally elastic brittle material that is subjected to quasi-static loading. However, the answer to the question of where — that is, in which direction — a large crack grows remains unresolved. A slew of criteria have been proposed over the decades, but comparisons with experiments have indicated that none of such criteria apply in general.
Directly guided by the mathematical structure of the regularized phase-field theory of fracture initiated by Kumar, Francfort, and Lopez-Pamies (J. Mech. Phys. Solids 112 (2018), 523–551), and motivated by the wide range of experiments that this theory has been validated against, this Letter introduces a new criterion to describe when and where large cracks grow in elastic brittle materials under quasi-static loading conditions. In a nutshell: the growth of a large crack takes place within and only within regions where the strength surface of the material has been exceeded, this in a manner such that the sum of the potential (that is, the elastic energy minus the work of the external loads) and surface energies are minimized. Importantly, this strength-constrained Griffith-energy-competition criterion is general in the sense that it applies to materials with any elasticity (linear or nonlinear) and any material symmetry (isotropic or anisotropic). In this Letter, for simplicity of presentation, attention is restricted to the most basic of settings, that of isotropic linear elastic brittle materials. Following its raison d’etre by means of a simple example and then general introduction, the proposed criterion is confronted with a set of classical experiments on glass.
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号