PROBLEMS IN Q-PARAMETER CALCULATIONS

摘要

The present work deals with determination of the sensitivity detached parameters describing fracture behaviour of body with crack with respect to the character change of true stress-strain curve. The typical low carbon cast steel stress-strain curve with dominant region of Lueders deformation was exerted. This paper presents the consideration on the change judgement of J-integral and Q-parameter as the base parameters of two parameters fracture mechanics. The attention is paid on the influence of deformation hardening exponent of the idealised true stress-strain material curve described by the Ramberg-Osgood relation to Q-parameter. All computations are based on the 3D elastic-plastic analyses using FEM and supported by mechanical tests.