PSI - Issue 38

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2021) 000 – 000 Available online at www.sciencedirect.com ScienceDirect

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 38 (2022) 621–630

FATIGUE DESIGN 2021, 9th Edition of the International Conference on Fatigue Design Numerical study of the influence of weld geometry variations on

fatigue life using the notch stress analysis Jinchao Zhu a , Zuheir Barsoum a and Rami Mansour b, * a Bars a b,

a Lightweight Structures, Department of Engineering Mechanics, KTH Royal Institute of Technology, Teknikringen 8, 100 44 Stockholm, Sweden b Solid Mechanics, Department of Engineering Mechanics, KTH Royal Institute of Technology, Teknikringen 8, 100 44 Stockholm, Sweden

© 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Fatigue Design 2021 Organizers Abstract Idealized geometry is typically used in standards for the fatigue life assessment of welded joints. In the presence of stochastic geometrical variations along the weld, the choice of the idealized geometry is however ambiguous. In the notch stress (NS) method with a fictitious notch radius r ref = 1 mm, the FAT 225 curve is derived for welds with relatively good quality in toe profiles. In the NS method with r ref = r actual + 1 mm, a lower FAT 200 curve is recommended. Both approaches neglect the stochastic variability in toe radius, toe angle and leg length along the weld. The aim of this paper is two-fold. First, a numerical comparison between both approaches in terms of their predicted fatigue life is performed for a non-load carrying fillet cruciform joints. The results show that the NS method with r ref = 1 mm and FAT 225 is substantially more conservative. Second, these methods are enhanced by replacing the deterministic stress concentration factor by a probability distribution computed using Monte Carlo simulation. It is shown that NS with r ref = 1 mm and FAT 225 does not predict any substantial influence of the stochastic variability in process parameters since the actual toe radius is not included in the analysis. However, the NS method with r ref = r actual + 1 mm and FAT 200 predicts a decrease in fatigue life when uncertainties in geometrical parameters is included. This numerical study paves the way for an experimental validation of the predicted influence of stochastic variability of geometrical parameters based on the stochastic notch stress analysis. © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Fatigue Design 2021 Organizers Keywords: Weld; Fatigue life; Notch stress analysis; Monte Carlo simulation; Stochastic geometrical variations; This is an open access article under the CC BY-NC-ND license (http

* Corresponding author. Tel.: +46-(0)73-600 18 36. E-mail address: ramimans@kth.se

2452-3216 © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Fatigue Design 2021 Organizers

2452-3216 © 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Fatigue Design 2021 Organizers 10.1016/j.prostr.2022.03.064