An integrated dynamic model of China＇s deep ocean mining system is developed and the fast simulation analysis of its longitudinal reciprocating motion operation processes is achieved. The seafloor tracked miner is bu...An integrated dynamic model of China＇s deep ocean mining system is developed and the fast simulation analysis of its longitudinal reciprocating motion operation processes is achieved. The seafloor tracked miner is built as a three-dimensional single-body model with six-degree-of-freedom. The track-terrain interaction is modeled by partitioning the track-terrain interface into a certain number of mesh elements with three mutually perpendicular forces, including the normal force, the longitudinal shear force and the lateral shear force, acting on the center point of each mesh element. The hydrodynamic force of the miner is considered and applied. By considering the operational safety and collection efficiency, two new mining paths for the miner on the seafloor are proposed, which can be simulated with the established single-body dynamic model of the miner. The pipeline subsystem is built as a three-dimensional multi-body discrete element model, which is divided into rigid elements linked by flexible connectors. The flexible connector without mass is represented by six spring-damper elements. The external hydrodynamic forces of the ocean current from the longitudinal and lateral directions are both considered and modeled based on the Morison formula and applied to the mass center of each corresponding discrete rigid element. The mining ship is simplified and represented by a general kinematic point, whose heave motion induced by the ocean waves and the longitudinal and lateral towing motions are considered and applied. By integrating the single-body dynamic model of the miner and the multi-body discrete element dynamic model of the pipeline, and defining the kinematic equations of the mining ship, the integrated dynamic model of the total deep ocean mining system is formed. The longitudinal reciprocating motion operation modes of the total mining system, which combine the active straight-line and turning motions of the miner and the ship, and the passive towed motions of the pipeline, are proposed and simulated with the developed 3D dynamic model. Some critical simulation results are obtained and analyzed, such as the motion trajectories of key subsystems, the velocities of the buoyancy modules and the interaction forces between subsystems, which in a way can provide important theoretical basis and useful technical reference for the practical deep ocean mining system analysis, operation and control.展开更多
为定量评估集装箱码头岸边作业坠箱事故发生概率,对其构建系统动力学(system dynamics,SD)模型。基于坠箱事故的故障树分析(fault tree analysis,FTA)结果,将事故因素按照“人-机-物-环-管”进行分类,分析因素发生的概率和基本事件相互...为定量评估集装箱码头岸边作业坠箱事故发生概率,对其构建系统动力学(system dynamics,SD)模型。基于坠箱事故的故障树分析(fault tree analysis,FTA)结果,将事故因素按照“人-机-物-环-管”进行分类,分析因素发生的概率和基本事件相互之间的影响关系。在验证利用SD模型得到的事故发生概率与FTA的定量计算结果具有一致性的基础上,考虑实际情况下各因素的动态特性和相互关系,得到利用SD模型得到的概率结果较FTA的概率结果更接近实际情况。采用SD模型在FTA的最小径集中选择安全策略,并通过模型仿真检验选择的安全策略能否使码头岸边作业坠箱事故发生概率下降到预期水平。给集装箱码头的建议:首先要针对人的因素采取安全措施,其次是机械因素,再次是管理因素。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51105386)the National Deep-Sea Technology Project of Development and Research(Grant No.DYXM-115-04-02-01)the Fundamental Research Funds for the Central Universities(Grant No.2011QNZT058)
文摘An integrated dynamic model of China＇s deep ocean mining system is developed and the fast simulation analysis of its longitudinal reciprocating motion operation processes is achieved. The seafloor tracked miner is built as a three-dimensional single-body model with six-degree-of-freedom. The track-terrain interaction is modeled by partitioning the track-terrain interface into a certain number of mesh elements with three mutually perpendicular forces, including the normal force, the longitudinal shear force and the lateral shear force, acting on the center point of each mesh element. The hydrodynamic force of the miner is considered and applied. By considering the operational safety and collection efficiency, two new mining paths for the miner on the seafloor are proposed, which can be simulated with the established single-body dynamic model of the miner. The pipeline subsystem is built as a three-dimensional multi-body discrete element model, which is divided into rigid elements linked by flexible connectors. The flexible connector without mass is represented by six spring-damper elements. The external hydrodynamic forces of the ocean current from the longitudinal and lateral directions are both considered and modeled based on the Morison formula and applied to the mass center of each corresponding discrete rigid element. The mining ship is simplified and represented by a general kinematic point, whose heave motion induced by the ocean waves and the longitudinal and lateral towing motions are considered and applied. By integrating the single-body dynamic model of the miner and the multi-body discrete element dynamic model of the pipeline, and defining the kinematic equations of the mining ship, the integrated dynamic model of the total deep ocean mining system is formed. The longitudinal reciprocating motion operation modes of the total mining system, which combine the active straight-line and turning motions of the miner and the ship, and the passive towed motions of the pipeline, are proposed and simulated with the developed 3D dynamic model. Some critical simulation results are obtained and analyzed, such as the motion trajectories of key subsystems, the velocities of the buoyancy modules and the interaction forces between subsystems, which in a way can provide important theoretical basis and useful technical reference for the practical deep ocean mining system analysis, operation and control.
文摘为定量评估集装箱码头岸边作业坠箱事故发生概率,对其构建系统动力学(system dynamics,SD)模型。基于坠箱事故的故障树分析(fault tree analysis,FTA)结果,将事故因素按照“人-机-物-环-管”进行分类,分析因素发生的概率和基本事件相互之间的影响关系。在验证利用SD模型得到的事故发生概率与FTA的定量计算结果具有一致性的基础上,考虑实际情况下各因素的动态特性和相互关系,得到利用SD模型得到的概率结果较FTA的概率结果更接近实际情况。采用SD模型在FTA的最小径集中选择安全策略,并通过模型仿真检验选择的安全策略能否使码头岸边作业坠箱事故发生概率下降到预期水平。给集装箱码头的建议:首先要针对人的因素采取安全措施,其次是机械因素,再次是管理因素。
