Combined macroscopic and microscopic approach to the fracture of metals. Annual progress report, 1982-1983

Significant progress was achieved in the development of accurate solutions for crack tip stress and deformation fields. Finite element studies were initiated. In the area of microstructural aspects of fracture processes in ductile alloys, we have begun an experimental study of load transfer as a strain hardening mechanism in two-phase alloys, in parallel with a finite element analysis of deformation of two-phase alloys. Work on the fracture process in dual-phase steels continues. As part of the continuing study of the fracture toughness of high strength steels, an attempt was made to interpret the fracture results in terms of the micro-fracture process beneath a crack or notch by which voids or microcracks initiate and link with the main crack. The study of hydrogen induced ductility losses has been extended to include the effects of strain state and level of triaxiality on the ductile rupture of a 1015-type steel.