R-curve testing and its relevance to structural assessment

Crack growth resistance can be substantially affected by the constraint conditions of a structural member which in turn are mainly a function of geometrical variables and the degree of plasticity. Standardized test methods are restricted to high constraint conditions as represented by deeply cracked bend-type specimens and may hence lead to conservative structural assessments. It is demonstrated that adjusted testing can be used to reduce the degree of conservatism. Due to rapidly increasing computer capabilities, a combination of conventional R-curve testing with micromechanical models emerges as an accurate tool which may permit routine evaluations of practical situations in the near future. (orig.)First published in 'Fatigue and Fracture of Engineering Materials and Structures 1998, 21 p. 1259-1271'Available from TIB Hannover: RA 3251(98/E/69) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Rissabstumpfung, Spaltbruch im Uebergangsbereich und stabiles Risswachstum - untersucht mit den Methoden der nichtlinearen Bruchmechanik

With 114 figs., 10 tabs.Copy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Suggestions for a modification of ASTM E 813 Workshop discussion

SIGLEReprint from ASTM Special Technical Testing Publication 856, 1985, p. 411-419 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Influence of specimen size on J-, J_m- and #delta#_5-R-curves for side-grooved compact-tension specimens

The influence of specimen size and geometry on R-curves has been studied for a pressure vessel steel and an aluminum alloy using side-grooved compact-tension specimens. The specimen thickness reduction (necking) was used to quantify changes of constraint in laboratory specimens. The results show that the crack tip opening displacement, #delta#_5, and the modified J-integral J_m, can correlate significantly more stable crack growth than the conventional J-integral. (orig.)Reprinted from: ASTM-STP--1171 (1993) p. 429-472Available from TIB Hannover: RA 3251(93/E/84) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Modifications of ASTM E 813-81 standard test method for an improved definition of Jlc using new blunting-line equation

SIGLEReprint from Special Technical Publication 945 (1988) p. 374-389, American Society for Testing and Materials, Philadelphia, PA (USA) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman