Mode I, quasi-static, steady state crack growth is analyzed for rate dependent materials under plane strain conditions in small scale yielding. The solid is characterized by an elastic-viscoplastic constitutive law and the plane ahead of the crack tip is embedded with a rate dependent fracture process zone. The macroscopic work of fracture of the material is computed as a function of the crack ...

A continuum damage mechanics (CDM) based constitutive model has been developed to describe elastic, plastic and damage behavior of porous rocks. The pressure sensitive inelastic deformation of porous rocks together with their damage mechanisms are studied for drained and undrained conditions. Fracture mechanics of microcrack andmicro-void nucleation and their coalescence are incorporated into t...

Recent three-point bend tests of size effect on the strength of geometrically scaled sandwich beams of three types – with no notches, and with notches at the upper or lower skin–foam interface, which were previously evaluated using simplified sandwich beam theory and equivalent linear elastic fracture mechanics, are now reanalyzed more accurately by finite elements. Zero-thickness interface ele...

0020-7683/$ see front matter 2008 Elsevier Ltd. A doi:10.1016/j.ijsolstr.2008.11.016 Abbreviations: ASTM, ASTM International; CC, co continuous cohesive zone method; CPE4I, bilinear inc elements; DACE, design and analysis of computer cantilever beam; DCZM, discrete cohesive zone metho finite element; LEFM, linear elastic fracture mech sampling; SLJ, single lap joint; TTL, trapezoidal tractio * ...

Conventional fracture closure models typically assume homogeneous formation. This assumption renders complex pressure analysis during shut-in insufficient at present. In this paper, we use a cohesive zone method (CZM)-based finite element model to obtain the and minimum horizontal principal stress of major branch based on fall-off analysis. Key factors including leak-off rate, injection time, a...

The objectives of this study were to test the fracture strength in vitro laminate veneers, partial veneers and composite restorations after aging analyze failure mode. Forty extracted, sound human teeth selected divided into four groups: 1) Control group (CG); 2) Conventional Laminate Veneer (CLV); 3) Partial (PLV); 4) Direct Composite Resin (DCR). veneer preparations with incisal overlap made ...

In this work we develop a new phase field method for modeling fracture in polycrystalline materials. Many studies addressed problem by combining cohesive models at the grain boundaries and damage bulk. paper, unified formulation is proposed framework. Anisotropic failure considered within grain. Each of preferential direction associated with variable. An additional variable dedicated to which a...