Dynamic Interactions of a Pipe System With a Seafloor Miner for Deep-Ocean Hardrock Mining

9531182钟现在的理论是基于结合一个新的概念，垂直管道连接到一个矿工和应用外部（控制）力在管道上，以控制管道-矿工的运动。整个管道采煤机系统的建模将水平管道与长而接近垂直的管道系统以及自推进式海底采煤机连接起来。沿着管道的弹性接头可以有效地改变轴向和弯曲特性。为了将外部（控制）力施加到接头上以控制管道的横向运动，将采用有限元（FEM）和组合（刚体）单元（RBE）对柔性接头进行建模。比较两种方法的精度和优点。销节点使整个系统的本征值为零，进入刚性模态，而自重作为垂直管道的内轴向力，进一步影响整个系统的本征值。换挡技术可以解决这个问题。在节点处安装非线性轴向阻尼器的三维非线性耦合响应将降低轴向应力，同时也会影响弯曲和扭转。矿机的土（沙）阻力将采用DEM（离散单元）和FEM两种方法进行建模。DEM建模将使用大量的一般几何形状的离散粒子。土壤颗粒的初步模拟表明，DEM模型在研究土壤颗粒的微观力学细节方面是非常有前途的。＊＊＊

9531182 Chung Present theory is based on incorporating a new concept of vertical pipe connecting to a miner and application of external (control) force on the pipe for the control of pipe- miner motions. Modeling of an entire pipe-miner system pin-joins a horizontal pipe to the long, near-vertical pipe system and to a self-propelling seafloor miner. The elastic joints along the pipe can be made effective in changing the axial, as well as, bending characteristics. To apply external (control) forces to the joints for the control of the lateral motion of the pipe, the flexible joints will be modeled by finite element (FEM), as well as combined (rigid body) element (RBE). The accuracy and advantages of the two methods will be compared. The pin joint leads the entire system to zero eigenvalue and rigid mode, and the weight, as the inner axial force of the vertical pipe, further influences the eigenvalues of the entire system. A shift technique will solve this problem. The proposed 3-D nonlinear coupled responses with nonlinear axial dampers installed at the joints will reduce the axial stress and also influence the bending and torsion, as well. Soil (sediment) resistance for the miner will be modeled by both DEM (discrete elements) and FEM. The DEM modeling will use a mass of discrete particles of general geometry. Preliminary modeling of soil particles indicates that DEM modeling is very promising to examine micromechanical details of the soil particles. ***