为了研究土壤不排水抗剪强度、落锚速度、锚尺寸及质量对船舶抛锚入泥深度的影响,基于耦合欧拉一拉格朗日方法建立了抛锚入泥深度数值分析模型。建模时采用八节点欧拉单元EC3D8R模拟土壤,采用八节点拉格朗日单元C3D8R模拟锚,并将其定义为约束于参考点的刚体;为减小边界效应对计算结果的影响,分别选取对应于8倍锚爪宽度与厚度及8倍锚杆高度的范围作为计算区域。模拟结果表明,抛锚入泥深度变化与土壤不排水抗剪强度增大成反比关系,且入泥深度变化幅值随不排水抗剪强度值的增大而逐渐变小;抛锚入泥深度变化率与锚质量变化率及土壤水平接触面积变化率的比值呈线性关系。
In order to identify the effects of soil undrained shear strength, anchor dropping speed, anchor size and weight on penetration depth, a numerical model for analyzing anchor penetration depth based on coupled Euler - Lagrangian method is established. In modeling, the Eight-node Euler unit EC3D8R is used for simulating soil and eight-node Lagrangian unit C3D8R is used for simulating anchor, which is defined as a rigid body con- strained on a reference point. To reduce the effect of the boundary effect on the calculation results, the calculation area is set with the thickness and width of 8 times of the fluke width and height of 8 times the height of anchor rod. Simulation results show that the penetration depth of dropped anchor has an inverse relationship with the undr- ained shear strength of soil. The variation of penetration depth also decreases with the increase of undrained shear strength value. The penetration depth change rate has a linear relationship with the ratio of the anchor weight change rate and the change rate of the horizontal contact area of soil.