The engineering treatment model (ETM) for pure power law and non-power law hardening materials

The Engineering Treatment Model (ETM) provides a set of simple formulae for estimating crack driving forces in terms of the crack tip opening displacement (CTOD), #delta#_5, which measures the CTOD at the specimen side surface, spanning the original crack tip over a gauge length of 5 mm, and the J-integral. Some new developments in the ETM have been made in this paper, which include: (1) extension of the ETM concept for piece-wise power law materials to pure power law and non-power law materials: (2) the J-integral being directly deduced, independent of #delta#_5; (3) a #delta#_5-ETM relationship for a growing crack. These new developments are validated by comparison with experimental results and finite element calculations. It has been shown that, using the deformation theory of plasticity and monotonic loading conditions, the ETM concept is valid over a wide range of materials and is able to deal with crack growth problems. (orig.)First published in 'Fatigue and Fracture of Engineering Materials and Structures 1998, 21 p. 1233-1248'Available from TIB Hannover: RA 3251(98/E/67) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman