Abstracts In this study, a multi-scale approach concept is introduced to estimate OPB (out of plane bending)-induced failure considering time-varying interlink bending stiffness by using both high-fidelity nonlinear-FEM (finite element method)-based local structural analysis and low-fidelity global-system-simulation program so that they can mutually be interfaced during the time-stepping procedure. In addition, time-varying interlink-angle measurement and its use with respect to the global-system simulation are devised. For the fully-coupled hull-mooring-riser global dynamics simulation, in-house program CHARM3D is extended to accommodate the time-varying OPB interlink stiffness. The hot spots for OPB fatigue are selected from the high-fidelity local FE analysis including residual stress after proof-loading test. It is clearly shown that interlink angles are under-estimated if chain-hawse is not modeled in the global simulation. The OPB interlink angles, bending moments, and accumulated fatigue damages greatly increase when the fairlead connection is changed from hinged to fixed condition. Moreover, fatigue damage is underestimated if the residual stress effect is not considered.

中文翻译：

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考虑时变链节弯曲刚度和导缆器条件的链系泊 OPB 诱导失效的多尺度方法

摘要在本研究中，引入了多尺度方法概念，通过使用基于高保真非线性 FEM（有限元方法）的局部结构，来估计 OPB（平面外弯曲）引起的失效，同时考虑时变互连弯曲刚度。分析和低保真全局系统仿真程序，以便它们可以在时间步长过程中相互连接。此外，设计了时变互连角测量及其在全球系统模拟中的应用。对于完全耦合的船体-系泊-立管全局动力学模拟，内部程序 CHARM3D 进行了扩展，以适应随时间变化的 OPB 互连刚度。OPB 疲劳的热点是从高保真局部有限元分析中选择的，包括验证加载测试后的残余应力。清楚地表明，如果在全局模拟中没有对链式锚链进行建模，则会低估互连角度。当导缆器连接从铰接状态变为固定状态时，OPB 互连角度、弯矩和累积疲劳损伤大大增加。此外，如果不考虑残余应力效应，则疲劳损伤被低估。