海洋环境下舰载系留气球缆绳与球体的动态仿真分析

目的研究舰载系留气球在海洋环境下对系留缆绳以及球体姿态的影响。方法采用ADAMS二次开发宏命令来建立离散化系留缆绳模型,并将离散化系留缆绳几何模型在相邻微段圆柱间添加Bushing轴套力,设置相关刚性系数和阻尼系数获得完整特效的缆绳模型。同时根据船用起重机的相关设计规范,考虑船体横摇5°和纵摇2°等运动影响,分析船体运动情况可知,纵摇时系留缆绳下端系固点位置较之横摇波动幅度更大,对缆绳的影响更大,因此主要研究船体纵摇2°情况下对于系留缆绳的影响,并分析对比船体静止以及船体纵摇2°情况下对于舰载系留气球系留缆绳以及球体姿态的影响。结果获得了在船体静止状态以及纵摇激励影响下舰载系留气球系留缆绳张力变化曲线以及球体姿态变化曲线。船体纵摇2°情况时,系留缆绳在仿真开始阶段承受冲击载荷较大,峰值达到150 kN,随后缆绳载荷基本在25 k N上下浮动。张力变化曲线整体呈现周期变化,周期与船体纵摇周期一致,为10 s。球体横滚角和航向角变化与船体静止状下仿真结果基本一致,球体俯仰角变化幅度较大。结论船体纵摇时会对系留缆绳带来较大的冲击载荷,同时对球体的俯仰姿态产生影响。该仿真结果对舰载系留气球的可行性分析和适装性研究以及系留缆绳的选用具有较大的指导意义。

Dynamic Simulation Analysis of Ship-borne Tethered Balloon Cable and Sphere in Marine Environment

Objective To study the influences of shipboard tethered balloon on the mooring rope and sphere in marine environment. Methods In this paper, the ADAMS secondary development macro command was used to establish the discretization mooring cable model; and the bushing force was added between the adjacent micro-segment cylinders of the discretization tethered cable geometry model. Relevant stiffness coefficient and damping coefficient were set to obtain the cable model of the complete special effect. Meanwhile, considering the movement effects of the hull roll 5° and the pitch 2°, the hull movement was analyzed according to the relevant design specifications of the marine crane. It can be seen that the position of the lower end of the mooring cable at the lower end of the tether was more fluctuating than the roll. The larger the amplitude, the greater the impact on the cable, so impact of the hull 2° on the tethered cable was mainly analyzed and the influence of the hull static and the hull pitch 2° on the tethered cable and the attitude of the ball on the ship was analyzed and compared. Results The tension curve of the tethered balloon tethered cable and the attitude change curve of the ball under the influence of the hull static state and the pitching excitation were obtained. The results showed that the tethered cable born a large impact load at the beginning of the simulation when the hull was tilted by 2°. When the peak value reached 150,000N, and the cable load was basically floating at 25000N. The tension change curve showed a periodic change as a whole, and the period was consistent with the hull pitch period of 10s. The ball roll angle and heading angle change were basically consistent with the hull static simulation results, and the ball pitch angle changed greatly. Conclusion When the hull is tilted, it will bring a large impact load to the tethered cable and affect the pitch attitude of the ball. The simulation results have great guiding significance on feasibility analysis and suitability of the carrier-based captive balloon and the selection of the tethered cable.