Abstract
The very high cycle fatigue behavior of S275J2+N flux-core arc welded joints was investigated using the ultrasonic fatigue testing method at a loading frequency of 20 kHz. A bespoke specimen design featuring the weld toe was employed to more suitably represent in-service welded joints than typical ultrasonic fatigue testing specimens. This revealed that fracture occurs above 10 million cycles, beyond the classically accepted fatigue limit. Additionally, comparative fatigue tests were performed at 10 Hz to investigate the frequency effect on the fatigue behavior. A 35% increase in fatigue strength was measured at 20 kHz when compared to 10 Hz, indicating that a correction must be considered in the use of ultrasonic fatigue testing data for design purposes. Fracture surfaces for both test frequencies showed similar morphologies and typical characteristics for fatigue failures of ductile metals.
| Original language | English |
|---|---|
| Pages (from-to) | 1529-1541 |
| Number of pages | 13 |
| Journal | Fatigue and Fracture of Engineering Materials and Structures |
| Volume | 48 |
| Issue number | 4 |
| Early online date | 14 Jan 2025 |
| DOIs | |
| Publication status | Published - 1 Apr 2025 |
Funding
The authors would like to acknowledge the support for this study (21/1/MIN/AM&D/1057), which was provided by the Weir Group PLC (WARC2011-SAA1, 2011) via its establishment of the Weir Advanced Research Centre (WARC) at the University of Strathclyde.
Keywords
- very high cycle fatigue
- welded joints
- ultrasonic fatigue testing
- frequency effect
- fracture surface analysis