An enhanced probabilistic model for cleavage fracture assessment accounting for local constraint effects |
| |
Authors: | Jörg Hohe Volker Hardenacke Sabrina Luckow Dieter Siegele |
| |
Affiliation: | Fraunhofer-Institut für Werkstoffmechanik IWM, Wöhlerstr. 11, 79108 Freiburg, Germany |
| |
Abstract: | Objective of the present study is the development of an enhanced model for the probabilistic cleavage fracture assessment of ferritic materials considering the conditions for both, nucleation and propagation of micro defects. In a first step, the local load and deformation history at the cleavage initiation spot is analysed numerically for a variety of fracture mechanics specimens. The experimental data base includes experiments on standard deep and shallow crack specimens with different geometries as well as novel small scale cruciform bending specimens. These specimens enable the application of an additional stress component along the crack front. Based on the results, a two-criteria concept for cleavage initiation is proposed, assuming that the propagation of existing micro defects is controlled by the maximum principal stress whereas the nucleation of potentially critical micro defects is governed by a combination of the local plastic strain and the local stress triaxiality at the respective material point. Based on these assumption, a probabilistic cleavage fracture model is formulated and validated against the experimental data base. |
| |
Keywords: | Cleavage fracture Ferritic material Probabilistic model Local approach Transferability |
本文献已被 ScienceDirect 等数据库收录! |