The Fracture Mechanics of Ductile Metals Theory
| Autor: | George Bockrath, James Glassco, Bahram Farahmand |
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| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | Fatigue and Fracture Mechanics of High Risk Parts ISBN: 9781461377535 Fracture Mechanics of Metals, Composites, Welds, and Bolted Joints ISBN: 9781461356271 |
| Popis: | Almost all metallic materials manifest some plastic deformation in the region at the crack tip before catastrophic crack propagation. The general principle from which the Griffith theory [1] (see Section 3.1 of Chapter 3) is derived is not limited to materials that obey Hooke’s law. The principle applies as well when dissipative mechanisms, such as plastic deformation, are present. Irwin and Orowan [2, 3] showed that Griffith’s principle can also be applied to materials that manifest ductile behavior, that is: $$\frac{\partial }{{\partial c}}\left[ {{{U}_{E}} - {{U}_{S}} - {{U}_{P}}} \right] = 0$$ (6.1) where U E is the stored energy, and U P is the energy consumed per unit thickness in plastic straining in the region at the crack tip. For ductile metals, where U P ≫ U S , the expression for surface energy, U S , was omitted from Eq. (6.1) to obtain: $$\frac{\partial }{{\partial c}}\left[ {{{U}_{E}} - {{U}_{P}}} \right] = 0$$ (6.2) |
| Databáze: | OpenAIRE |
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