Improvement factors for the design of welded joints subjected to high frequency mechanical impact treatment

Ummenhofer, Thomas; Weidner, Philipp

doi:10.1002/stco.201310027

Cited by 11 publications

(4 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The fatigue capacity of structural steels in offshore applications is affected by various parameters, each of which can influence the quality and the mechanical properties. Although there are many reports on fatigue testing on structural steels, this review covers a representative number of studies 18–47 focusing on S355 butt‐welded structural steels. These structural steels have been tested using a variety of test setups, loading conditions, welding types, and other postprocessing variables.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Corrosion surface morphology‐based methodology for fatigue assessment of offshore welded structures

Okenyi,

Afazov,

Mansfield

et al. 2023

Fatigue Fract Eng Mat Struct

View full text Add to dashboard Cite

This work employed a novel corrosion‐based fatigue model to determine the fatigue life of offshore welded structures to enable the fatigue assessment of welds under corrosive conditions. In addition to the material's ultimate strength, endurance limit, and stress ratio (mean stress effect), the model includes a corrosion factor concept to account for the impact of corrosion pits on the fatigue performance of welded S355 steel, which is the novel contribution in this paper. X‐ray computed tomography scans of corroded S355 specimens in a salt spray chamber were characterized. Surface texture characterization was employed to obtain surface roughness, size, and aspect ratio of corrosion pits. The corrosion factor was determined based on notch and surface fatigue theories using the characterized pit size, aspect ratio, and surface roughness. Fatigue S‐N curves were then predicted for critical pits and compared against the fatigue code DNVGL‐RP‐C203 and experimental data from the literature. The novel approach combining corrosion characterization method with corrosion‐based fatigue model for the prediction of fatigue S‐N curves provided a minor deviation of only 2.8% between predicted and measured data. This approach can potentially be integrated into predictive frameworks for the remaining life assessment of offshore structures.

show abstract

Section: Introductionmentioning

confidence: 99%

“…In addition to the reviewed literature, 18–47 S‐N data from the design code standards BS7606, 50 DNVGL‐RP‐C203, 51 BS‐EN1993‐1‐9, 52 and IIW recommendations 53 were also considered. The codes provided S‐N curve values in both air and corrosive conditions in artificial seawater (ASW) and salt spray chambers (SSC).…”

Section: Introductionmentioning

confidence: 99%

Corrosion surface morphology‐based methodology for fatigue assessment of offshore welded structures

Okenyi,

Afazov,

Mansfield

et al. 2023

Fatigue Fract Eng Mat Struct

View full text Add to dashboard Cite

show abstract

“…The method is based on the acceleration of a pin made of hardened steel towards the weld toe by an appropriate mechanism. Still, the HFMI enhancement of fatigue strength depends on many parameters (5). Compressive residual stresses (RS), which counterbalance the tensile welding residual stresses (WRS), are introduced, the notch effect is reduced and the treated surface becomes locally hardened.…”

Section: Introductionmentioning

confidence: 99%

“…The effectiveness of the method has been confirmed for various geometries, plate thicknesses and nominal strengths of parent material. Still, the HFMI enhancement of fatigue strength depends on many parameters (5). FE simulation of HFMI could act alternatively and/or supplementary to the cost ineffective fatigue tests.…”

Section: Introductionmentioning

confidence: 99%

FE Simulation of High Frequency Mechanical Impact (HFMI) Treatment – First Results

2019

Self Cite

View full text Add to dashboard Cite

High Frequency Mechanical Impact treatment is investigated numerically in the present paper. A first-step numerical dynamic analysis is carried out using the solver LS-Dyna. The treatment of an unnotched component of S355 is simulated. The strain rate dependent material parameter Cowper-Symonds is calibrated for the investigated material based on data from literature. Goal of the present analysis is to act a first step for a robust engineering approach, which will calculate with sufficient preciseness the residual stresses introduced by this post-weld treatment. The calculated residual stresses of the present investigation are compared with respective measurements found in literature. Deviation between measured and simulated residual stresses indicates the need for further improvement of the present model.

show abstract

Effect of increased yield strength, R-ratio, and plate thickness on the fatigue resistance of high-frequency mechanical impact (HFMI)–treated steel joints

Leitner

Barsoum

2020

Weld World

View full text Add to dashboard Cite

In 2016, the International Institute of Welding (IIW) published a recommendation for high-frequency mechanical impact (HFMI) treatment for improving the fatigue strength of welded joints. Since the publication of the HFMI recommendations, numerous of studies have been published with a considerable amount of new fatigue test data focusing on various aspects of the improvement; influence of base material yield strength, and loading and thickness effects. Since the data was scarce covering some of the aspects when the recommendation was published, re-evaluating the recommendation with these new test data, presented within this work, will further validate and extend the recommendations. The analysis reveals that the recommended improvement of fatigue classes based on the base material yield strength is well applicable. In addition, the reduction of fatigue classes for higher R-ratios up to the defined value of R = 0.52 is well considered. Finally, the practicability of the thickness correction factor is also confirmed by leading to a conservative fatigue assessment. The ratio of the statistically evaluated FAT class to the recommended value is shown to be conservative with a value of above one for almost every data set; however, even the ratio is below one in some minor cases, every single test data point in this study is assessed conservatively validating the applicability of the recommendation.

show abstract

Improvement factors for the design of welded joints subjected to high frequency mechanical impact treatment

Cited by 11 publications

References 10 publications

Corrosion surface morphology‐based methodology for fatigue assessment of offshore welded structures

Corrosion surface morphology‐based methodology for fatigue assessment of offshore welded structures

FE Simulation of High Frequency Mechanical Impact (HFMI) Treatment – First Results

Effect of increased yield strength, R-ratio, and plate thickness on the fatigue resistance of high-frequency mechanical impact (HFMI)–treated steel joints

Contact Info

Product

Resources

About