Fatigue strength improvement of high strength steel welded joints treated by high frequency mechanical impact
Event details
| Date | 08.11.2012 |
| Hour | 12:15 › 13:15 |
| Speaker | Prof. Gary Marquis |
| Location |
GC C330
|
| Category | Conferences - Seminars |
Abstract: In the past decade, high frequency mechanical impact (HFMI) has significantly developed as a reliable, effective and user-friendly method for post-weld fatigue strength improvement technique for welded structures. The development of an IIW best practice guideline for implementing HFMI has
been hindered by the lack of directly comparable experimental data for numerous HFMI methods. In this study, nominally identical longitudinal non-load carrying attachments in high strength steel, fy = 690 MPa, were manufactured at a single location and randomly distributed to four HFMI equipment
manufacturers for treatment. Specimens were subsequently returned and fatigue tested on a single machine using identical variable amplitude loading histories. Detailed specimen alignment, weld profile and HFMI groove measurements were done for each specimen and X-ray diffraction based residual
stress measurements were performed on 10 specimens. While clear differences were observed, the HFMI groove dimensions and the resulting residual stress state following treatment were generally similar. Experimental results indicate that all of the HFMI improved welds from the four different HFMI
equipment manufacturers satisfied the previously proposed characteristic S-N line based on both the material yield strength and the specimen geometry. Results of the study are valuable and promising with respect to the development of a future guideline. The goal of the study has not been to compare
treatments, so specific data points are not associated specific HFMI equipment manufacturers.
Short Bio :
Gary Marquis is Professor of Mechanics of Materials, Aalto University School of Engineering. He received his degrees in mechanical engineering from University of Illinois at Urbana-Champaign (BSc, MCs), and Helsinki University of Technology (PhD). He is a worldwide known specialist in the field of fatigue of steel components and structures. He has published numerous papers and a reference book on multi-axial fatigue with Prof. Darrell Socie (http://books.sae.org/book-r-234). He is the president of Commission XIII of the International Institute of Welding (IIW) "fatigue of welded components and structures", which is the most active commission in the organization with 50 active members from 20 countries.
been hindered by the lack of directly comparable experimental data for numerous HFMI methods. In this study, nominally identical longitudinal non-load carrying attachments in high strength steel, fy = 690 MPa, were manufactured at a single location and randomly distributed to four HFMI equipment
manufacturers for treatment. Specimens were subsequently returned and fatigue tested on a single machine using identical variable amplitude loading histories. Detailed specimen alignment, weld profile and HFMI groove measurements were done for each specimen and X-ray diffraction based residual
stress measurements were performed on 10 specimens. While clear differences were observed, the HFMI groove dimensions and the resulting residual stress state following treatment were generally similar. Experimental results indicate that all of the HFMI improved welds from the four different HFMI
equipment manufacturers satisfied the previously proposed characteristic S-N line based on both the material yield strength and the specimen geometry. Results of the study are valuable and promising with respect to the development of a future guideline. The goal of the study has not been to compare
treatments, so specific data points are not associated specific HFMI equipment manufacturers.
Short Bio :
Gary Marquis is Professor of Mechanics of Materials, Aalto University School of Engineering. He received his degrees in mechanical engineering from University of Illinois at Urbana-Champaign (BSc, MCs), and Helsinki University of Technology (PhD). He is a worldwide known specialist in the field of fatigue of steel components and structures. He has published numerous papers and a reference book on multi-axial fatigue with Prof. Darrell Socie (http://books.sae.org/book-r-234). He is the president of Commission XIII of the International Institute of Welding (IIW) "fatigue of welded components and structures", which is the most active commission in the organization with 50 active members from 20 countries.
Practical information
- General public
- Free
Organizer
- Prof. Nikolas Geroliminis & Prof. Katrin Beyer
Contact
- Prof. Alain Nussbaumer