The Weibull Stress Parameters Calibration upon the Toughness Scaling Model between Cracks Having Different Constraint

0178068 - UFM-A 20033086 RIV CZ eng C - Konferenční příspěvek (zahraniční konf.)
Kozák, Vladislav - Vlček, Libor
The Weibull Stress Parameters Calibration upon the Toughness Scaling Model between Cracks Having Different Constraint.
International Conference on Structural Mechanics in Reactor Technology /17./. Praha: International Association for Structural Mechanics in Reactor Technology, 2003, s. Paper G03-2.
[International Conference on STRUCTURAL MECHANICS IN REACTOR TECHNOLOGY /17./. Praha (CZ), 17.08.2003-22.08.2003]
Grant CEP: GA ČR GA106/01/0342; GA ČR GA106/02/0745
Výzkumný záměr: CEZ:AV0Z2041904
Klíčová slova: static tests of the three point bend specimens * constraint * Weibull stress
Kód oboru RIV: JL - Únava materiálu a lomová mechanika

An extensive investigation has been carried out on the sensitivity parameters determination describing the fracture behaviour of body with crack with respect to the character change of true stress-strain curve with dominant region of Lueders deformation.Consequently,its convenient substitution has been tested.This paper presents the consideration on the change judgement of J-integral and constraint as the base parameters of two-parameters fracture mechanics.The Weibull stress model for cleavage fracture of cast steel requires calibration of two micromechanics parameters (m,ó u).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 ó w is investigated.Local material parameters have been calculated arising from Beremin approach and calibration is based on various approaches.Methods are 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.The fracture resistance has been assessed using data from static tests of there point bend specimens.
Trvalý link: http://hdl.handle.net/11104/0074962