Fracture Model for Structured Quasibrittle Materials
V. D. Kurguzov1, N. S. Astapov1, I. S. Astapov2
1Lavrent'ev Institute of Hydrodynamics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090 Russia
2Research Institute of Mechanics, Moscow, 119192 Russia
Keywords: fracture criteria, prefracture zone, characteristic size of structural element, quasi–ductile fracture diagram
Abstract
We analyze the applicability of a modified Leonov—Panasyuk—Dugdale model to the description of the propagation of a mode I crack in structured materials under plane stress conditions. For quasi-brittle materials, refined formulas of the critical length of the prefracture zone and the critical load containing a structural parameter are proposed. The Kornev model is extended to the case of quasi-ductile materials. Numerical simulation of plastic zones in square plates of a bimetal and a homogeneous material under quasi–static loading is performed. In the numerical model, the equations of deformable solid mechanics are expressed in the Lagrangian formulation, which is the most preferred for large-strain deformations of elastoplastic materials. The results of the numerical experiments are consistent with the results of calculations using the analytical model for the fracture of structured materials.
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