This paper presents a method of quasistatic energy analysis for characterizing the fracture behaviour of a slender D.C.B. specimen having two parallel beam arms of low bending stiffness. Examples chosen are in-plane tension and anti-plane shear problems, which exhibit linear and nonlinear load-displacement relationships, respectively. The results derived analytically agree well with those obtained experimentally for both examples, thus successfully demonstrating the versatility of the quasistatic energy analysis in fracture studies.
Stability of crack propagation for the geometries considered is analysed and found to be favourable unless there is a large negative value of dG/da. Negative dG/da was attained by contaminating portions of an uncracked specimen, and unstable crack propagation was observed experimentally in the contaminated regions.
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