TY - JOUR A1 - Baer, Wolfram A1 - Bösel, Dieter A1 - Eberle, Arno A1 - Klingbeil, Dietmar T1 - Determination of dynamic crack resistance of ductile cast iron using the compliance ratio key curve method JF - Engineering fracture mechanics KW - Dynamic crack resistance curve KW - Ductile cast iron KW - Single-specimen method KW - Key curve KW - Compliance ratio method PY - 2010 DO - https://doi.org/10.1016/j.engfracmech.2009.06.015 SN - 0013-7944 SN - 1873-7315 VL - 77 SP - 374 EP - 384 PB - Elsevier Science CY - Kidlington AN - OPUS4-20822 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Baer, Wolfram A1 - Eberle, Arno A1 - Klingbeil, Dietmar ED - Klingbeil, D. ED - Vormwald, M. ED - Eulitz, K.-G. T1 - The impact of ductile cast iron fracture behaviour on dynamic fracture mechanics R-curve testing using key curve methods T2 - 18th European conference on fracture (ECF 18) - Fracture of materials and structures from micro to macro scale (Proceedings) N2 - 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. T2 - 18th European conference on fracture (ECF 18) - Fracture of materials and structures from micro to macro scale CY - Dresden, Germany DA - 2010-08-30 KW - Damage and fracture behaviour KW - Ductile cast iron KW - Dynamic crack resistance curve KW - Key curve PY - 2010 SN - 978-3-00-031802-3 IS - Paper 160 SP - 1 EP - 8 AN - OPUS4-22273 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -