深水吊放缆绳受力分析方法研究及有限元模拟

Analysis Method of Force on Suspended Cable in Deep Sea

目前国内外对于深水安装方面的研究主要集中在水下设备的运动响应,而对于连接水下设备与浮体船之间的安装缆绳的动态响应研究很少。为此,对吊放缆绳划分微分单元,建立缆绳受力分析模型,根据莫里森方程推导出微分单元的水平、垂向以及轴向拉力表达式,基于弯矩平衡理论推导出缆绳的水平偏移表达式,为深水吊放缆绳受力分析提供了一种有效的方法。然后选取荔湾3-1绞车安装法下放420 t管汇的算例,综合考虑环境载荷和缆绳材质等因素,采用有限元软件对吊放缆绳进行强度校核,提取缆绳在不同水深的水平位移和轴向位移,并与数值解进行对比,对比结果验证了理论方法的正确性。

Currently, the deep-sea installation research in China and other countries is mainly concentrated on movement response of underwater equipment, but less on dynamic response of cable installation in connecting underwater equipment and floating boat. In this regard, the suspended cable is divided into differential units to es- tablish the analysis model of force on cables. Based on the Morison Formula, the expressions of horizontal, vertical and axial tension of differential units are worked out. Based on bending moment balance theory, the horizontal mi- gration expression of cable has been worked out, which can serve as an effective method to analyze the force on suspended cable in deep sea. Taking the installation method of Liwan 3 - 1 cable hoist to set down 420 t manifolds as example, considering environmental loads and materials used for cable, finite element software is utilized to verify the strength of suspended cable and work out the horizontal and axial displacements of cable at different water depths. The results are compared with solutions given by numerical simulation, which in the end has proved the va- lidity of the theoretical method.