Subsized Specimens for Fracture Resistance Characterization Including Transferability Issues

0468064 - ÚFM 2017 RIV JP eng O - Others
Dlouhý, Ivo - Stratil, Luděk - Šiška, Filip
Subsized Specimens for Fracture Resistance Characterization Including Transferability Issues.
2016
R&D Projects: GA ČR GJ15-21292Y
Institutional support: RVO:68081723
Keywords : fracture toughness * crack resistance curve * transferability * crack tip constraint * subsized specimen
Subject RIV: JL - Materials Fatigue, Friction Mechanics

The fracture mechnics parameters characterise the stress singularity in front of the crack tip. At the existence of a small plastic zone at the crack tip (Small Scale Yielding (SSY)) conditions the fracture mechnics parameter characterises the crak tip conditions. The single parameter (e.g. K, J or CTOD) can be applied as a geometry-independent fracture criterion. Any surpassing of the SSY conditions causing decrease of the level of the stressses in the vicinity of the crack tip. The single-parameter fracture mechanics then breaks down and fracture toughness depends on the size and geometry of the test specimen. Small Specimen Test Technique has been solved for two miniature specimen types. The test results are discusssed from the point of view of validity of fracture toughness characteristics. The quantification of the constraint at the crack tip using FEA, T-stress and Q-parameter is performed. Correcrion of fracture toughness values corresponding to the SSY conditions is given.
Permanent Link: http://hdl.handle.net/11104/0267241