深海多金属结核生长模拟及宏观形貌研究

研究旨在提出深海多金属结核生长的数值模拟方法，以获取典型的结核宏观形貌，为后续结核输运过程的冲击碎裂仿真提供几何模型。根据已有的深海多金属结核采样研究结果，假定矿物沉积速率满足正态分布。将多阶段时变随机沉积模型嵌入ABAQUS UMESHMOTION子程序中，通过控制网格节点移动实现了结核多阶段随机生长模拟，给出了结核不同生长阶段的外形及截面特性模拟结果。分析了鱼骨、鲨鱼牙齿、板岩、鹅卵石等典型不同核心物质及矿物沉积速率变异性对结核生长过程的影响，确定了核心物质在海床淤泥中埋置深度对结核生长形态的影响。研究表明：基于网格节点移动的结核生长模拟技术可有效处理结核几何拓扑变化较小的生长过程，核心物质的初始形状及其在海床上的埋置深度是影响结核形貌的主要原因，而矿物沉积速率的变异性则主要影响结核表面的光滑度。

Study on growth simulation and macromorphology of deep-sea polymetallic nodules

In this study, a numerical simulation method for the growth of deep-sea polymetallic nodules was proposed to obtain the typical macroscopic morphology of nodules, and provide a geometric model for the impact fragmentation simulation of nodules durig the transport process. Based on the sampling and detection results of deep-sea polymetallic nodules, it is assumed that the mineral deposition rate satisfies the normal distribution. The multistage random deposition model was embedded into ABAQUS UMESHMOTION subroutine, and the multistage random growth of nodules was simulated by controlling the movement of mesh nodes. The simulated morphology and section characteristics of nodules in different growth stages were given. The effects of different typical core materials, such as fish bone, shark tooth, slate and cobblestone, and the variability of mineral deposition rate on the growth process of nodules were analyzed, and the effects of the buried depth of core materials in the seabed silt on the growth morphology of nodules were determined. Research shows that: the nodular growth simulation technology based on mesh node movement can effectively deal with the growth process of nodular with small change of geometry topology. The initial shape of the core material and the embedment depth on the sea floor is the main factor affecting the morphology of nodular, while the variability of mineral deposition rate mainly affect the surface smoothness of the nodular.