Abstract
According to the IIW recommendation, the fatigue strength of welded steel joints is defined as independent of the base material in case of the as-welded condition. However, post-treatment techniques can improve the fatigue performance of welded structures, especially for increased base material strengths. Therefore, this paper investigates the effect of TIG dressing, as common post-weld treatment method, on the fatigue strength of high-strength steel S700 cruciform joints. The statistically evaluated fatigue test results reveal a significant increase of the nominal fatigue strength from FAT 90 for the as-welded up to 182 MPa for the TIG-dressed state. The experiments are further compared to recommended and suggested design curves applying both nominal as well as local stress approaches. Focusing on the TIG-dressed state, the suggested increase in nominal stresses is well validated leading to a conservative assessment. In addition, the proposed slope in the finite life region with a value of m1 = 4 shows a sound fit to the statistically evaluated value of m1 = 4.7 for the test results. The local fatigue strength estimation is performed based on a recent proposal using the theory of critical distances. Therefore, linear elastic numerical analysis of the investigated specimens is performed. Again, the resulting S-N curves agree well to the experiments validating the proposed local design approach
Original language | English |
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Pages (from-to) | 2585-2594 |
Number of pages | 10 |
Journal | Welding in the World |
Volume | 66 |
Issue number | 12 |
Early online date | 2022 |
DOIs | |
Publication status | Published - Dec 2022 |
Keywords
- Fatigue strength assessment
- High-strength steel
- Local approach
- TIG dressing
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
Fields of Expertise
- Mobility & Production