The impact of ductile cast iron fracture behaviour on dynamic fracture mechanics R-curve testing using key curve methods
- Dynamic fracture mechanics characteristics are required for design and safety proof of advanced ductile cast iron (DCI) components. In this paper, the analytical compliance ratio (CR) and numerical finite element (FE) key curve methods were investigated for dynamic Rcurve testing. Two DCI materials, a purely ferritic and a ferritic one with 18 % of pearlite, were tested at room temperature (RT) and -40 °C. The special focus is on the impact of the materials damage and fracture behaviour on performance and limitations of the investigated methods. Systematic metallographic and fractographic microstructural analyses were performed accompanying the test program. Summarizing systematics of the specific damage behaviour and fracture mechanisms were developed taking microstructure, loading rate, specimen geometry and test temperature into account. There has been a change from ductile to brittle fracture mechanism observed at -40 °C with ferritic DCI and even at RT with ferritic-pearlitic DCI.Dynamic fracture mechanics characteristics are required for design and safety proof of advanced ductile cast iron (DCI) components. In this paper, the analytical compliance ratio (CR) and numerical finite element (FE) key curve methods were investigated for dynamic Rcurve testing. Two DCI materials, a purely ferritic and a ferritic one with 18 % of pearlite, were tested at room temperature (RT) and -40 °C. The special focus is on the impact of the materials damage and fracture behaviour on performance and limitations of the investigated methods. Systematic metallographic and fractographic microstructural analyses were performed accompanying the test program. Summarizing systematics of the specific damage behaviour and fracture mechanisms were developed taking microstructure, loading rate, specimen geometry and test temperature into account. There has been a change from ductile to brittle fracture mechanism observed at -40 °C with ferritic DCI and even at RT with ferritic-pearlitic DCI. The ferritic-pearlitic DCI did not show Rcurve behaviour at -40 °C and only single Juc values could be determined. Furthermore, with ferritic-pearlitic DCI, random pearlite shares in the ligament caused the relation between loading rate, force-deflection record and crack extension not to remain uniquely defined. Therefore, the FE key curve method proofed not to be applicable since the FE model was based on homogeneous isotropic material and ductile failure mode only. The analytical CR key curve method worked well only with selected combinations of microstructure, specimen geometry and temperature. In summary it has to be concluded that a robust, accurate and sufficiently simple dynamic key curve method that was suited for application in quality control of industrial relevant DCI qualities cannot be provided currently.…
Autor*innen: | Wolfram BaerORCiD, Arno Eberle, Dietmar Klingbeil |
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Persönliche Herausgeber*innen: | D. Klingbeil, M. Vormwald, K.-G. Eulitz |
Dokumenttyp: | Beitrag zu einem Sammelband |
Veröffentlichungsform: | Verlagsliteratur |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | 18th European conference on fracture (ECF 18) - Fracture of materials and structures from micro to macro scale (Proceedings) |
Jahr der Erstveröffentlichung: | 2010 |
Herausgeber (Institution): | Deutscher Verband für Materialforschung und -prüfung e.V. (DVM) |
Ausgabe/Heft: | Paper 160 |
Erste Seite: | 1 |
Letzte Seite: | 8 |
Freie Schlagwörter: | Damage and fracture behaviour; Ductile cast iron; Dynamic crack resistance curve; Key curve |
Veranstaltung: | 18th European conference on fracture (ECF 18) - Fracture of materials and structures from micro to macro scale |
Veranstaltungsort: | Dresden, Germany |
Beginndatum der Veranstaltung: | 2010-08-30 |
Enddatum der Veranstaltung: | 2010-09-03 |
ISBN: | 978-3-00-031802-3 |
Verfügbarkeit des Dokuments: | Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access") |
Bibliotheksstandort: | Sonderstandort: Publica-Schrank |
Datum der Freischaltung: | 19.02.2016 |
Referierte Publikation: | Nein |