Characterization of fatigue crack growth with the configurational force concept

Produktbeschreibung

How can fatigue crack growth be correctly characterized in presence of significant plastic ­deformation? A well-known approach is to apply the experimental cyclic J-integral ∆Jexp. However, the application of ∆Jexp is questionable, since it presumes, like the classical J-integral, deformation theory of plasticity, which is not applicable for cyclic loading and crack extension. This book presents the physically correct characterization of fatigue crack growth in elastic-plastic materials by using the incremental plasticity cyclic J-integral ∆Jep, which is derived from the configurational force concept. New insights are obtained into longstanding questions: Is the application of ∆Jexp correct? What is the most important mechanism for crack growth retardation after an overload? It is shown that ∆Jexp equals ∆Jep only for the limiting case of a non-propagating fatigue crack. In general, care should be taken when using ∆Jexp since it can lead to a non-conservative assessment of the fatigue lifetime.

Keywords: 334318, 34318, 343, Fortschritt-Berichte VD, Reihe 18, Configurational force concept, Crack driving force, Cyclic J-integral, Incremental theory of plasticity, Low-cycle fatigue, Fatigue crack growth, Overload effect, Crack closure, Residual stresses,