Abstract The degree of bending (DoB) characterizes the member through-the-thickness stress distribution which has a profound effect on the fatigue behavior of tubular joints commonly found in steel offshore structures and the determination of DoB values is essential for improving the accuracy of fatigue life estimation. Multi-planar joints are an intrinsic feature of offshore tubular structures and the multi-planarity might have a considerable effect on the DoB values at the brace-to-chord intersection. Nevertheless, for multi-planar joints which cover the majority of practical applications, much fewer investigations have been reported on the DoB due to the complexity and high cost involved. In the present research, data extracted from the stress analysis of 81 finite element (FE) models, verified using available parametric equations, was used to study the effects of geometrical parameters on the DoB values in multi-planar tubular XT-joints subjected to two types of axial loading. Parametric FE study was followed by a set of the nonlinear regression analyses to develop four new DoB parametric equations for the fatigue analysis and design of axially loaded multi-planar XT-joints.

中文翻译：

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几何参数对承受轴向载荷的海上结构多平面管状 XT 接头弯曲度 (DoB) 的影响

摘要 弯曲度 (DoB) 表征了构件全厚度应力分布，这对钢海上结构中常见的管接头的疲劳行为具有深远的影响，而 DoB 值的确定对于提高疲劳精度至关重要。寿命估计。多平面接头是海上管状结构的固有特征，多平面性可能对支撑弦交叉处的 DoB 值产生相当大的影响。然而，对于涵盖大多数实际应用的多平面关节，由于涉及的复杂性和高成本，关于 DoB 的调查报告要少得多。在本研究中，从 81 个有限元 (FE) 模型的应力分析中提取的数据，使用可用的参数方程进行验证，用于研究几何参数对承受两种轴向载荷的多平面管状 XT 接头的 DoB 值的影响。参数有限元研究之后是一组非线性回归分析，以开发四个新的 DoB 参数方程，用于轴向加载多平面 XT 接头的疲劳分析和设计。