Application of weldment design guidelines to fatigue life prediction of steel welded tubular joints, part I: single-channel constant and variable amplitude loading
Abstract
Most studies based on design guidelines focus on life prediction of welded joints under uniaxial constant amplitude (CA) loading conditions, whereas shear and variable amplitude (VA) loading cases are less emphasized. Also, life prediction procedures are mostly applied to weldments with full weld penetration and limited information is available for welded joints with partial weld penetration. In part I of this two-part publication, popular design guidelines of British Standard (BS) 7608, International Institute of Welding (IIW), and Eurocode 3 (EC3) are reviewed and applied to fatigue life prediction of steel welded tubular joints under single-channel axial load and torsion with constant and variable amplitude loading conditions. Analyses of multi-channel axial and torsion loading cases based on these guidelines are addressed in part II. The welded joints featured start/stop and partial weld penetration. The standard fatigue classes for fully penetrated welds resulted in reasonable accuracy for tubular welded joints with partial penetration and IIW resulted in more accurate life estimations than EC3 and BS-7608. VA estimations based on the three guidelines were accurate within a factor of 2, while shear life estimations were more conservative, mostly within a factor of 5. VA estimations according to EC3 were less conservative due to using a unit damage sum value, as opposed to 0.5 by the other guidelines. The differences in VA life estimations by the three guidelines are attributed to the variations in damage sum value advised for analysis and the extensions of CA design curves for VA applications in HCF regime.
Publication Title
Welding in the World
Recommended Citation
Razi, A., Fatemi, A., & Farajian, M. (2026). Application of weldment design guidelines to fatigue life prediction of steel welded tubular joints, part I: single-channel constant and variable amplitude loading. Welding in the World https://doi.org/10.1007/s40194-026-02511-1
