冰振下海洋平台上部天然气管线振动分析

渤海辽东湾的导管架平台在海冰作用下会产生比较剧烈的振动。冰激振动除了可引起导管架结构的疲劳破坏，还会引起平台上部管线的疲劳破坏与法兰的松动，因而有必要分析平台在冰振作用下的上部天然气管线振动问题。为此，基于现场监测，建立了管线系统振动力学模型，并采用有限元数值模拟的方法，考虑了管系的复杂支撑、管件、管系设备等因素对管系的影响，计算出冰振下JZ202平台上部主要天然气管系的模态、位移、转角响应及动应力幅值。结果表明，冰振对天然气管线的动态响应有重要的影响，在冰区海洋平台上部管道设计时必须加以考虑，并提出了提高管系抗振的措施。

Dynamic Response Analysis on Gas Piplines Exposure to Ice-induced Vibration on Offshore Platform

Sea ice will cause the offshore jacket platform structure to vibrate strenuously in Bohai Sea. The ice-induced vibrations of offshore structure will not only result in the fatigue failure of jacket but also lead to the associated accidents of pipelines on the platform. So it is necessary to study on the problem of gas pipelines exposure to ice-induced vibration on the platform. This paper analyzes dynamic response by ice-induced vibration for gas pipelines on the platform based on the data monitored on the platforms of JZ202 in Bohai Sea. Then a vibration mechanics model of gas pipelines is built up by means of elastic mechanics theory. With finite element modeling, the natural frequencies, the displacement, and the amplitude of turning angle response induced by deck vibration are calculated with full consideration put on the influence of the complex supports, devices, and elbows of pipelines. The results show that ice-induced vibration has great effect on the dynamic response for the pipeline system, which should be surely put into consideration when pipeline system is to be designed on offshore platforms in ice areas. Finally, some measures are suggested here to improve the anti-vibration performance of pipeline system.