{"title":"Degree of Bending in Axially Loaded Tubular KT-Joints of Offshore Structures: Parametric Study and Formulation","authors":"Hamid Ahmadi, Shadi Asoodeh","volume":102,"journal":"International Journal of Civil and Environmental Engineering","pagesStart":707,"pagesEnd":717,"ISSN":"1307-6892","URL":"https:\/\/publications.waset.org\/pdf\/10001611","abstract":"The fatigue life of tubular joints commonly found in\r\noffshore industry is not only dependent on the value of hot-spot stress\r\n(HSS), but is also significantly influenced by the through-thethickness\r\nstress distribution characterized by the degree of bending\r\n(DoB). The determination of DoB values in a tubular joint is essential\r\nfor improving the accuracy of fatigue life estimation using the stresslife\r\n(S\u2013N) method and particularly for predicting the fatigue crack\r\ngrowth based on the fracture mechanics (FM) approach. In the\r\npresent paper, data extracted from finite element (FE) analyses of\r\ntubular KT-joints, verified against experimental data and parametric\r\nequations, was used to investigate the effects of geometrical\r\nparameters on DoB values at the crown 0\u00b0, saddle, and crown 180\u00b0\r\npositions along the weld toe of central brace in tubular KT-joints\r\nsubjected to axial loading. Parametric study was followed by a set of\r\nnonlinear regression analyses to derive DoB parametric formulas for\r\nthe fatigue analysis of KT-joints under axial loads. The tubular KTjoint\r\nis a quite common joint type found in steel offshore structures.\r\nHowever, despite the crucial role of the DoB in evaluating the fatigue\r\nperformance of tubular joints, this paper is the first attempt to study\r\nand formulate the DoB values in KT-joints.","references":"[1] M. P. M. Connolly, A fracture mechanics approach to the fatigue\r\nassessment of tubular welded Y and K-joints. 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