The Transferability of Brittle Fracture Toughness Characteristics

0177672 - UFM-A 20013176 RIV SIGLE US eng C - Konferenční příspěvek (zahraniční konf.)
Kozák, Vladislav - Holzmann, Miloslav - Dlouhý, Ivo
The Transferability of Brittle Fracture Toughness Characteristics.
Structural Mechanics in Reactor Technology - SMiRT 16. North Carolina State University: Center for Nuclear Power Plant Structures, Equipment and Piping, 2001, s. čl. 1079.
[International Conference on Structural Mechanics in Reactor Technology /16./. Washinghton DC (US), 12.08.2001-17.08.2001]
Grant CEP: GA ČR GA101/00/0170; GA ČR GV101/96/K264
Výzkumný záměr: CEZ:AV0Z2041904
Klíčová slova: local approach * toughness scalling models * cast ferritic steel
Kód oboru RIV: JL - Únava materiálu a lomová mechanika

In this paper, the use of the Weibull stress as a measure of the failure probability of cracked body is tested. The Weibull stress model for cleavage fracture of cast steel requires calibration of two micromechanics parameters. Weibull stress seems to be a parameter for prediction of cleavage failure of cracked bodies and the study is focused on the assessment of the effects of constraint loss on cleavage fracture toughness (Jc). To quantify the effects of constraint variation on the cleavage fracture toughness the form of the toughness-scaling model based on the Weibull stress is investigated. Local material parameters have been calculated arising from Beremin approach and calibration is based on the Gao and Ruggieri approach. Method is based on weakest link assumption and incremental fracture probability, which depends not only on the maximum principal stress, but also on the equivalent plastic strain. Accepting this approach to the analysis of local criteria for cleavage fracture the location and shape parameters m were calculated using FEM for notched tensile bars having various types of geometry too. The aim of the paper can be seen in fracture toughness transfer and correction from pre-cracked specimens to small scale yielding (SSY) represented by 1T (SENB) specimens. The fracture resistance has been assessed using data from static tests of the bend specimens. The standard finite element method package Abaqus was applied and the manganese cast steel considered for storage and transport container for spent nuclear fuel (SKODA) was selected as an experimental material.
Trvalý link: http://hdl.handle.net/11104/0074591