Quasi-Brittle Fracture of Compact Specimens with Sharp Notches and U-Shaped Cuts
V. M. Kornev, A. G. Demeshkin
Lavrent'ev Institute of Hydrodynamics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia
Keywords: хрупкое и квазихрупкое разрушение, маломасштабная текучесть, необходимые и достаточные критерии разрушения, упругопластический материал, краевая трещина, U-образный вырез, brittle and quasi-brittle fracture, small-scale creep, necessary and sufficient criteria of fracture, elastoplastic material, edge crack, U-shaped cut
Abstract
A two-parameter (coupled) discrete-integral criterion of fracture is proposed. It can be used to construct fracture diagrams for compact specimens with sharp cracks. Curves separating the stress-crack length plane into three domains are plotted. These domains correspond to the absence of fracture, damage accumulation in the pre-fracture region under repeated loading, and specimen fragmentation under monotonic loading. Constants used for the analytical description of fracture diagrams for quasi-brittle materials with cracks are selected with the use of approximation of the classical stress-strain diagrams for the initial material and the critical stress intensity factor. Predictions of the proposed theory are compared with experimental results on fracture of compact specimens with different radii made of polymethylmethacrylate (PMMA) and solid rubber with crack-type effects in the form of U-shaped cuts.
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