Options
Fatigue life extension of existing welded structures via high frequency mechanical impact (HFMI) treatment
Citation Link: https://doi.org/10.15480/882.3458
Publikationstyp
Journal Article
Date Issued
2021-04-09
Sprache
English
TORE-DOI
TORE-URI
Journal
Volume
239
Article Number
112234
Citation
Engineering Structures 239: 112234 (2021-07-15)
Publisher DOI
Scopus ID
Publisher
Elsevier Science
High Frequency Mechanical Impact (HFMI) is one of the post-weld treatment methods. In this study, comparative axial fatigue tests were conducted on as-welded and HFMI-treated welded transverse attachment details. The test results demonstrated the efficiency of HFMI-treatment in fatigue life extension of cracked welded structures, providing that the existing crack size is less than 1.2 mm. Cracks were created in some specimens through fatigue testing before HFMI-treatment, while other specimens were not subjected to any fatigue loading prior to treatment. Many of the treated specimens ran-out after 10 million cycles of loading when tested at a stress range of 150 MPa. Therefore, the stress range was increased to 180 MPa or 210 MPa. No remarkable difference was found between the fatigue strength of the crack-free and the cracked treated specimens. It was found that the induced compressive residual stress can exceed the material yield limit, and reach a depth larger than 1.5 mm in most of the cases. The induced compressive residual stress, the local material hardening, the increase in weld toe radius, the change in crack orientation and the shallowness of the crack size were the causatives of the obtained long fatigue lives of the HFMI-treated specimens. Besides, linear elastic fracture mechanics calculations were conducted to predict the fatigue lives of as-welded and HFMI-treated details. The results were in agreement with the experiment. Moreover, the calculations showed that the initial crack size, the clamping stress and the induced compressive residual stress were the main factors behind the scatter in fatigue lives.
Subjects
Crack repair
Existing structures
Fatigue life extension
High frequency mechanical impact
Pre-fatigue
Steel bridges
DDC Class
600: Technik
620: Ingenieurwissenschaften
More Funding Information
The work presented in this paper has been conducted within the research project ‘LifeExt’ with funding from the Swedish Transport Administration (Trafikverket) and the Swedish Innovation Agency (Vinnova).
Publication version
publishedVersion
Loading...
Name
1-s2.0-S0141029621003849-main.pdf
Size
12.43 MB
Format
Adobe PDF