{"title":"The severity of local undercut on fatigue life of welded joints","authors":"Abinab Niraula , Heikki Remes","doi":"10.1016/j.ijfatigue.2025.108949","DOIUrl":null,"url":null,"abstract":"<div><div>Fatigue cracks most commonly initiate from local weld imperfections, such as undercuts, that have a significant impact on the fatigue life of the structure. The influence of local undercut on fatigue has been traditionally classified on the level of workmanship for quality control purposes, and a systematic quantified approach to determine the influence of local undercut on fatigue strength is needed. In this paper, the influence of the 3D undercut geometry on the fatigue strength of welded joints is investigated to quantify the severity of different undercut sizes and shapes in butt welded joints. Systematic elastic and elasto-plastic analyses are performed on butt-welded joints with different steel grades and local undercut geometries under multiple stress ranges. As a result, a semi-analytical formulation is proposed to estimate the elastic stress concentration factor for butt welds with an undercut, considering the 3D undercut geometry as well as the global weld geometry. Furthermore, a novel undercut severity index for fatigue analysis is introduced and validated, considering the variation of the local undercut 3D shape, weld bead geometry, stress ranges, and materials.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"197 ","pages":"Article 108949"},"PeriodicalIF":6.8000,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Fatigue","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S014211232500146X","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/3/24 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Fatigue cracks most commonly initiate from local weld imperfections, such as undercuts, that have a significant impact on the fatigue life of the structure. The influence of local undercut on fatigue has been traditionally classified on the level of workmanship for quality control purposes, and a systematic quantified approach to determine the influence of local undercut on fatigue strength is needed. In this paper, the influence of the 3D undercut geometry on the fatigue strength of welded joints is investigated to quantify the severity of different undercut sizes and shapes in butt welded joints. Systematic elastic and elasto-plastic analyses are performed on butt-welded joints with different steel grades and local undercut geometries under multiple stress ranges. As a result, a semi-analytical formulation is proposed to estimate the elastic stress concentration factor for butt welds with an undercut, considering the 3D undercut geometry as well as the global weld geometry. Furthermore, a novel undercut severity index for fatigue analysis is introduced and validated, considering the variation of the local undercut 3D shape, weld bead geometry, stress ranges, and materials.
期刊介绍：
Typical subjects discussed in International Journal of Fatigue address:
Novel fatigue testing and characterization methods (new kinds of fatigue tests, critical evaluation of existing methods, in situ measurement of fatigue degradation, non-contact field measurements)
Multiaxial fatigue and complex loading effects of materials and structures, exploring state-of-the-art concepts in degradation under cyclic loading
Fatigue in the very high cycle regime, including failure mode transitions from surface to subsurface, effects of surface treatment, processing, and loading conditions
Modeling (including degradation processes and related driving forces, multiscale/multi-resolution methods, computational hierarchical and concurrent methods for coupled component and material responses, novel methods for notch root analysis, fracture mechanics, damage mechanics, crack growth kinetics, life prediction and durability, and prediction of stochastic fatigue behavior reflecting microstructure and service conditions)
Models for early stages of fatigue crack formation and growth that explicitly consider microstructure and relevant materials science aspects
Understanding the influence or manufacturing and processing route on fatigue degradation, and embedding this understanding in more predictive schemes for mitigation and design against fatigue
Prognosis and damage state awareness (including sensors, monitoring, methodology, interactive control, accelerated methods, data interpretation)
Applications of technologies associated with fatigue and their implications for structural integrity and reliability. This includes issues related to design, operation and maintenance, i.e., life cycle engineering
Smart materials and structures that can sense and mitigate fatigue degradation
Fatigue of devices and structures at small scales, including effects of process route and surfaces/interfaces.
京公网安备 11010802042870号
京ICP备2023020795号-1
分享
求助内容：
应助结果提醒方式：
扫码关注我们
