船舶落锚撞击海底电缆事故频发，严重威胁海缆安全稳定运行。依托广西防城港某海上风电项目，采用无限元法模拟半无限地基及海缆的辐射效应，在Abaqus中建立船锚-海缆-海床的有限元-无限元耦合模型，获取海缆落锚撞击时的变形响应规律，并研究了海床性质、撞击角度、落锚质量和撞击速度等因素对海缆损伤变形的影响。研究结果表明：1）海缆锚砸过程可分为冲击段、转折段和回弹段3个阶段，铠装钢丝层是主要的承载构件，内部结构层动态应力演化过程相较铠装钢丝层存在滞后现象；2）海缆局部凹陷变形随土体弹性模量增大而增大，海缆整体弯曲变形随土体弹性模量的增大而减小；3）光纤单元的纵向压缩率随冲击角度的增大而减小，冲击角度对铠装层凹陷变形影响不大，对于三芯复合海缆，在冲击角0°下出现光纤单元截面变形最大值，在冲击角60°时出现最小值；4）船锚的质量对海缆整体弯曲变形影响较大，船锚的速度对海缆局部凹陷变形影响较大。

英文摘要:

Ship anchor drop incidents causing impacts on submarine cables are frequent and pose significant threats to their safe and stable operation. Based on an offshore wind power project in Fangchenggang, Guangxi, the study uses the infinite element method to simulate the radiation effects of the semi-infinite foundation and submarine cables. An Abaqus-based finite element-infinite element coupling model of the ship anchor-submarine cable-seabed system was established to capture the deformation response during anchor drop impacts on the cable. The study also investigates the influence of seabed properties, impact angle, anchor mass, and impact velocity on the cable's damage and deformation. The results indicate the following: 1) The anchor impact process on the cable can be divided into three phases: the impact phase, transition phase, and rebound phase; the armored steel wire layer is the main load-bearing component, and the internal structural layer exhibits hysteresis delay in dynamic stress evolution relative to the armored steel wire layer. 2) The local depression deformation of the cable increases with the increase of the soil’s elastic modulus, while the overall bending deformation of the cable decreases with the increase of the soil's elastic modulus. 3) The longitudinal compression rate of the fiber optic units gradually decreases with an increase in the impact angle, while the impact angle has little effect on the depression deformation of the armored layer. For the three-core composite submarine cable, the maximum deformation of the fiber optic unit cross-section occurs at an impact angle of 0°, and the minimum occurs at an impact angle of 60°. 4) The mass of the ship anchor significantly affects the overall bending deformation of the submarine cable, while the anchor's velocity has a greater impact on the local indentation deformation of the cable.

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