Abstract
The loading history of engineering components can influence the behaviour of defects in service. This paper presents, the results of a numerical study aimed at using the Gurson ductile damage model, calibrated against J R-curve data, to simulate load-history effects on ductile tearing behaviour in austenitic materials. The work has demonstrated that ductile crack growth resistance is influenced by sub-critical crack growth by an intervening mechanism such as fatigue. Fatigue crack growth under a positive R-ratio leads to increase in subsequent tearing resistance through three main mechanisms: (i) re-sharpening of the crack tip; (ii) crack extension through the fracture process zone; and (iii) cyclic loading effects on void development. The ratio of minimum to maximum stress during fatigue loading (R-ratio) has been shown to influence subsequent tearing resistance, with an R-ratio of 0.2 generally leading to a greater enhancement in tearing resistance than an R-ratio of 0.1. This behaviour is due to the influence of R-ratio on void development ahead of the fatigue crack tip. Finally, relevant experimental data compare favourably with the predicted J R-curves. © 2005 Elsevier Ltd. All rights reserved.
| Original language | English |
|---|---|
| Pages (from-to) | 905-916 |
| Number of pages | 11 |
| Journal | International Journal of Pressure Vessels and Piping |
| Volume | 82 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - Dec 2005 |
Keywords
- Ductile tearing
- Fatigue
- Gurson model
- R6
- Stainless steel
- Tearing-fatigue