Notch Effects in Fatigue and Fracture

0177631 - UFM-A 20013280 RIV SIGLE NL eng M - Monography Chapter
Dlouhý, Ivo - Chlup, Zdeněk - Holzmann, Miloslav
Local characteristics of (brittle) failure assessed from Charpy type specimen.
0-7923-6841-X. In: Notch Effects in Fatigue and Fracture. Dordrecht: Kluwer Academic publishers, 2001 - (Pluvinage, G.; Gjonaj, M.), s. 127-146. II. Mathematics, Physics and Chemistry. NATO Science Series.
R&D Projects: GA AV ČR IAA2041003
Institutional research plan: CEZ:AV0Z2041904
Keywords : local approach * transferability * brittle fracture initiation
Subject RIV: JL - Materials Fatigue, Friction Mechanics

Local characteristics of predominantly brittle fracture have been analysed arising from the primary data obtained by using Charpy type specimens. Two model ferritic microstructures have been selected for knowledge presentation that differ significantly in their carbide thickness and scatter of fracture toughness data. Based on the deterministic approach to the analysis of cleavage failure under the notch root, the local fracture criteria have been evaluated using fracture micromechanism assessment combined with FEM calculations. The effective distances have been calculated from normal stress distributions and compared with depth of initiation point below the notch root measured from fracture surfaces. Accepting the Beremin approach to the analysis of cleavage failure criteria the local fracture parameters have been calculated for Charpy type specimen. For the microstructures investigated the Weibull stresses (location parameters) were related to cleavage fracture stresses determined supposing deterministic nature of cleavage fracture events at initiation. Microstructural and microfractographic reasons for scatter of data and connection to between local fracture criteria were determined.
Permanent Link: http://hdl.handle.net/11104/0074550