Dikhtyarenko Y. Stress-strain state near tip of a mode I crack in angular point of the interface materials with considering of the prefracture zones

Analytical solutions of the static symmetric problems of computing of small-scale prefracture zones at the end of a mode I crack which comes out from angular point of the broken interface of two brittle or quasi-brittle materials were built under the conditions of plane strain by the Wiener-Hopf method in the model Leonov-Panasyuk-Dugdale. Stress-strain state in the tip of crack after the formation of the prefracture zones were investigated. Expressions for the determination of the length of the prefracture zones and the direction of these lines were found. The conditions under which a crack propagates along the interface, branches in one of the materials or crosses the line of the interface without branching for the elastic material were analyzed. The opening of the crack in its tip and stress field after the formation of the prefracture zones and the ultimate load at which is the crack shift was determined. The stress-strain state in the crack tip for the quasi-brittle material after the formation of the plastic strips was investigated. Based on these results, it shows that the stress concentration at the corner point remains, so after the appearance of the two side plastic strips from a mode I crack tip you should expect new areas - plastic zones on continuing of the crack. Calculation of plastic zone prefracture and crack opening we should use the model "trident". The expressions of the full crack opening due to the development of the side plastic strips and plastic strip on the continuation of the crack and stress field after the formation of the plastic zone are obtained.