caa a22 4500 469125195 CHVBK 20180323133149.0 cr unu---uuuuu 170328e19920401xx s 000 0 eng 10.1007/BF00035355 doi (NATIONALLICENCE)springer-10.1007/BF00035355 Estimation procedure for the Weibull parameters used in the local approach [Elektronische Daten] [F. Minami, A. Brückner-Foit, D. Munz, B. Trolldenier] The local approach was recently proposed by Beremin and Mudry for evaluating the statistical behaviour of toughness results of materials. This approach introduces a stress parameter σ w , termed the Weibull stress, as a measure of the fracture resistance of materials instead of the conventional toughness parameters such as K c, δ c and J cl (critical stress intensity factor, CTOD and J-integral, respectively). The Weibull stress σ w obeys the Weibull distribution with the two parameters m and σ u (the shape and the scale parameter, respectively). The first parameter m is normally estimated to be 22 irrespective of the kind of material. In this paper a procedure for the determination of the Weibull parameters m and σ u is developed. This procedure consists of the determination of the plastic zone ahead of the crack tip, from which cleavage fracture originates, and of the maximum likelihood estimation of the parameters m and σ u based on the stress distribution in the plastic zone. Calculations using this procedure confirm that the distribution of the Weibull stress σ w is a material property independent of specimen thickness, and in particular that the shape parameter m depends on the material, e.g. m≃12 for a German reactor pressure vessel steel (20 Mn Mo Ni 5 5). Using these parameters for the distribution of the Weibull stress the size effect in fracture toughness values is predicted and an improved agreement between theory and experiments is obtained compared to the Weakest Link model. Kluwer Academic Publishers, 1992 Minami F. Karlsruhe Nuclear Research Centre, IMF IV, P.O. Box 3640, D-7500, Karlsruhe, Germany aut Brückner-Foit A. Karlsruhe Nuclear Research Centre, IMF IV, P.O. Box 3640, D-7500, Karlsruhe, Germany aut Munz D. Institute for Reliability and Failure Analysis, University of Karlsruhe, P.O. Box 3640, D-7500, Karlsruhe, Germany aut Trolldenier B. Institute for Reliability and Failure Analysis, University of Karlsruhe, P.O. Box 3640, D-7500, Karlsruhe, Germany aut International Journal of Fracture Kluwer Academic Publishers 54/3(1992-04-01), 197-210 0376-9429 54:3<197 1992 54 10704 https://doi.org/10.1007/BF00035355 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00035355 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Minami F. Karlsruhe Nuclear Research Centre, IMF IV, P.O. Box 3640, D-7500, Karlsruhe, Germany aut NATIONALLICENCE 700 1- Brückner-Foit A. Karlsruhe Nuclear Research Centre, IMF IV, P.O. Box 3640, D-7500, Karlsruhe, Germany aut NATIONALLICENCE 700 1- Munz D. Institute for Reliability and Failure Analysis, University of Karlsruhe, P.O. Box 3640, D-7500, Karlsruhe, Germany aut NATIONALLICENCE 700 1- Trolldenier B. Institute for Reliability and Failure Analysis, University of Karlsruhe, P.O. Box 3640, D-7500, Karlsruhe, Germany aut NATIONALLICENCE 773 0- International Journal of Fracture Kluwer Academic Publishers 54/3(1992-04-01), 197-210 0376-9429 54:3<197 1992 54 10704 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer