1st European Mechanics of Materials Conference on Local Approach to Fracture '86 - 96'
J. Phys. IV France 06 (1996) C6-23-C6-32
Influence of Strain History on Ductile Failure of SteelJ. Arndt, H. Majedi and W. Dahl
IEHKI Technical University Aachen, Intzerstrasse 1, 52072 Aachen, Germany
Notched tensile bars of a high strength structural steel were loaded to void coalescense. The resuIts show that the damage curve determined using radially loaded specimens is not valid for specimens under non-radial loading. The results of the experiments with different load histories of notched tensile bars show, that a single parameter criterion like a damage parameter is not sufficient to describe the initiation process of void coalescense. The shape of the voids and the triaxiality at initiation exhibit a strong influence on the initation values. There are two ways to describe the initiation. A simple one considers a critical combination of void growth rate, triaxiality and plastic strain at initiation. The other one uses a shape factor to describe the shape of the voids and calculates the initiation values. Both models work with an accuracy in the order of the experimental scatter.
© EDP Sciences 1996