共查询到17条相似文献，搜索用时 203 毫秒
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海洋防腐工程中受阴极保护金属构筑物表面的电位电流分布常常是不均匀的,而金属表面的电位电流只有在一定范围内才能使构筑物受到有效和适当的保护.尤其是复杂而庞大的海洋钢结构物(如滨海电厂钛管凝汽器)阴极保护系统的设计和监测较复杂,此阴极保护下电化学场的计算,对评价阴极保护效果,优化阴极保护设计有重要意义.采用电化学场中的拉普拉斯(Laplace)方程,使用四节点四面体和合适的形状函数对水室表层和复杂结构体系周围场域进行离散.用有限元计算法,通过对各单元的分布和整个求解区域的总和,建立了两种不同金属组成复杂结构体系的三维有限元数学模型. 相似文献
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海洋钢结构阴极保护电场的数值模拟仿真和计算是当前海洋腐蚀、阴极保护研究和工程实践中一个重要的研究方向。研究海底管线的腐蚀状态就必须准确测定管线表面的电位分布,而实际测量中深海管线表面电位分布难以直接测量。构建了海水中钢管线的阴极保护数学模型,采用以边界元法为基础的数值计算方法,利用Matlab开发了均匀电解质中电位分布的计算软件,实测中通过对腐蚀电场海水区域环境电场的测量,就可实现不接触测量管线表面电位的目的。最后通过海洋实测验证了计算结果的可靠性,证明了基于Matlab的数值仿真计算引入阴极保护设计中是行之有效的。 相似文献
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本文利用蒙特卡洛法模拟分析海洋平台Ｅ３６Ｚ３５钢表面疲劳裂纹扩展速率,并确定了算式中的参数分布规律及相关性。通过计算数据与试验数据的对比分析,表明蒙特卡洛法模拟结果合理、可靠。 相似文献
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The environmental conditions around the first offshore HZ 21- 1 steel wellhead platform in the South China Sea are characterized by deep water, frequent typhoons, rough waves, high water temperature, severely corrosive seawater, and thick fouling organism attachments. The design and effectiveness of galvanic anode protection system are presented, and several methods are described, which are the calculation method of the protective current density considering the variation of water depth, the method of determining protection parameters considering various factors, the arrangement of anodes based on potential distribution and current requirements at different water depths, and the method of anode installation. Finally the effect of the accuracy of selected cathodic protection parameters on the economic benefits of offshore projects is also discussed.. 相似文献
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A full time-domain analysis program is developed for the coupled dynamic analysis of offshore structures. For the hydrodynamic loads, a time domain second order method is developed. In this approach, Taylor series expansions are applied to the body surface and free-surface boundary conditions, and the Stokes perturbation procedure is then used to establish the corresponding boundary value problems with time-independent boundaries. A higher-order boundary element method (HOBEM) is developed to calculate the velocity potential of the resulting flow field at each time step. The free-surface boundary condition is satisfied to the second order by fourth order Adams–Bashforth–Moultn method. An artificial damping layer is adopted on the free surface to avoid the wave reflection. The mooring-line/tendon/riser dynamics are based on the rod theory and the finite element method (FEM), with the governing equations described in a global coordinate system. In the coupled dynamic analysis, the motion equation for the hull and dynamic equations for mooring-lines/tendons/risers are solved simultaneously using the Newmark method. The coupled analysis program is applied for a truss Spar motion response simulation. Numerical results including motions and tensions at the top of mooring-lines/risers are presented, and some significant conclusions are derived. 相似文献
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In this study a typical tension-leg type of floating platform incorporated with the tuned liquid column damper (TLCD) device is studied. The purpose is to find an effective and economic means to reduce the wave induced vibrations of the floating offshore platform system. The floating offshore platform has been widely applied for the offshore exploitation such as operation station, cross-strait bridges, floating breakwater and complex of the entertainment facilities. For offshore platform being employed as a public complex the stability and comfort to stay will be the major concern besides the safety requirement. Therefore, how to mitigate the vibration induced from waves and similar environmental loading becomes an important issue. The TLCD system utilizing the water sloshing power to reduce the vibration of the main structure, a newly developed device that could effectively reduce the vibrations for many kinds of structure is the first-time employed in the floating platform system. In both the analytical and experimental results it is found that the accurately tuned TLCD system could effectively reduce the dynamic response of the offshore platform system in terms of the vibration amplitude and the resonant frequency. 相似文献