Fatigue life estimation of welded structures enhanced by combined thermo-mechanical treatment methods
Artikel i vetenskaplig tidskrift, 2021

Different post-weld treatment methods are used to strengthen welded joints that are subjected to cyclic loading. Combining High-Frequency Mechanical Impact (HFMI) treatment with Tungsten Inert Gas (TIG) remelting is rather a new concept. In this paper, the fatigue lives of welded transverse attachments treated by HFMI-treatment, TIG-remelting, or the combination of both are estimated using fatigue damage modelling and finite element deletion. The change in local topography and residual stresses due to treatment are evaluated numerically and incorporated in the analysis. The local hardness is measured by a Vickers tester and incorporated by increasing the elemental ultimate strength. The analysis demonstrates the superiority of the combined treatment because of the introduced compressive residual stress and the improvement in topography. The analysis also shows that the damage is less distributed after the combined treatment than both individual treatments. Besides, the capability of the TIG-HFMI combination in treating existing welded structures with remaining embedded fatigue crack is proven. Besides, available fatigue test results on combined TIG-HFMI treatment shows that this combination gives always longer fatigue life than the characteristic fatigue lives of the treated details by any of the treatment methods. However, many aspects such as TIG arc and HFMI indenter positioning, and indentation and fusion depth should be taken into consideration when the combined treatment is to be applied to existing structures.

Abaqus

Steel

Fatigue

Residual stress

Damage

HFMI

Crack repair

FEM

Welding

Hardness

Författare

Hassan al-Karawi

Chalmers, Arkitektur och samhällsbyggnadsteknik, Konstruktionsteknik

Journal of Constructional Steel Research

0143-974X (ISSN)

Vol. 187 106961

Rekomendationer för HFMI-behandling av stålbroar - utveckling av dimensioneringsmetoder och tekniska kravspecifikationer

Trafikverket (TRV 2020-68167), 2020-07-01 -- 2022-06-30.

LifeExt-2-Implementation

VINNOVA (2021-01045), 2021-05-31 -- 2024-05-30.

Drivkrafter

Hållbar utveckling

Ämneskategorier

Infrastrukturteknik

Styrkeområden

Livsvetenskaper och teknik (2010-2018)

DOI

10.1016/j.jcsr.2021.106961

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Senast uppdaterat

2021-10-11