Fatigue life estimation of the weld joint in K-node of the offshore jacket structure using stochastic finite element analysis

Fatigue strength assessment of complex welded structures with severe force concentrations along a weld seam

“…To study the fatigue strength of complex connections, full-scale tests are needed. Full-scale fatigue tests have been performed to investigate weld toe failure [1,3,21] but very little test data can be found for weld root failure in load carrying cruciform connections and mainly simplified structures have been tested [9,11,20]. In this paper fatigue tests are presented for complex full-scale specimens representing the pillar connection of a cruise ship.…”

“…Large thin-walled structures include complex welded connections such as tubular joints in offshore or steel bridge structures [1,2] and cruciform connections in ships [3]. The common feature of these complex connections is structural discontinuity resulting from unsymmetrical connections, differences in plate thickness, partially penetrated fillet welds, and one-sided welding.…”

“…The influence of secondary bending stress in the weld is not considered in the nominal weld stress approach or local nominal weld stress approaches since they consider only the weld force component normal to the weld and the area of the weld cross-section; see Eq. (1). The simplest approach to also include the bending moment component is the structural weld stress approach.…”

Numerical analysis and discussion on the hot-spot stress concept applied to welded tubular KT joints

“…Larsen et al [2] estimated the fatigue life of the K-type joint of an offshore jacket; in this study three finite element models of different weld geometries were calibrated from an experimental model. One of the numerical models was built using the real 3D digitized weld geometry, another with the weld geometry proposed by offshore design codes, and the third model without any weld geometry representation.…”

“…Jacket-type support structures are one of the most common types of offshore support structures representing 95% of fixed offshore structures [1]. These structures are preferred when the sea depth becomes moderate to deep, when compared to other fixed support structures such as monopile foundations [2]. The main type of loading which these structures are submitted to is due to the sea waves that have characteristics of stochastic events [3,4].…”