Lefm brittle and ductile fractures as described by the T-criterion

✍ Scribed by N.P. Andrianopoulos; P.S. Theocaris

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 675 KB
• Volume: 30
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(88)90249-4

✦ Synopsis

Fracture is connected with limited amounts of plastic expansion, else materials fail by general yielding. This obvious presupposition of fracture may take two limiting algebraic expressions corresponding to extreme brittle and extreme ductile cases, respectively. These hvo expressions are inserted into the formulation of the T-criterion of fracture. The first (brittle) expression results in predictions for the critical fracture stress similar to those of the existing 'brittle' fracture criteria. The second (ductile) one coincides with the existing 'ductile' version of the T-criterion. Experimental evidence gathered from ductile materials agrees well with the 'ductile' version of this criterion, the same being not true in the case of "brittle" criteria when their predictions are compared with the results from a typical brittle material (PMMA). Finally, a discussion, based on the experimental results, is presented, showing that the assumption of a constant radius of the so-called 'core-region' or plastic zone in case of brittle materials seems to be misleading.