Investigating fracture mechanics concepts by testing thermomechanically rolled steels in order to ensure the safety of building components
This research project examined fracture mechanics failure concepts in thermomechanically rolled steels up to a yield strength of 510 MPa and a medium strength structural steel St 52-3. The toughness of these steels was tested in instrumented Charpy tests, fracture mechanics tests and tensile tests with CNT- and DENT-type specimens. A number of tests were carried out with a notch position in the heat affected zone or weldment of submerged arc welds, followed by metallographic post-examination of the broken specimens. The J(R)-Da crack growth resistance curves of the steels were determined by compact-specimens, with and without side grooves, and by three point bend specimens according to several fracture mechanics standards. The transition temperatures of instrumented Charpy tests, fracture mechanics tests and large notched tensile tests were compared. The maximum loads of the large notched tensile specimens were estimated by the K(I)-concept, the plastic limit load concept, CTOD-based concepts, the EPRI estimation scheme and the R6-method. These methods provided results which agreed closely with the testing results. To guarantee a safe prediction of structural parts, additional safety factors should be applied, especially when using the EPRI-estimation scheme or the R6-method.
Bibliographic Reference: EUR 13174 DE (1991) 160 pp., FS, ECU 15
ISBN: ISBN 92-826-2080-8
Record Number: 199110294 / Last updated on: 1994-12-02
Original language: de
Available languages: de