海洋平台分振结构减振效果的试验研究

根据渤海海洋环境的特点，提出了一种新的平台分振结构，以减小流冰引起的平台振动，同时考虑了地震和波浪对此分振结构的影响．分振结构的设想是将平台立柱分成内管和外管，外管通过斜撑杆和桩腿沉箱连接，内管则支承平台甲板．内管和外管在水线附近可以相联或分开．为此，设计并制造了一个钢结构模型，用集中的随机载荷分别输入到分振模型的各有关位置，以模拟流冰、地震和波浪等外载荷，分别在空气和水环境中作了减振效果试验．减振效果则利用测点振动响应的传递函数的概念来分析，减振效果是一个无量纲系数，仅是频率的函数．试验结果证明，此结构形式对减振有相当好的效果．

An Experimental Study on Vibration Reduction Effect of Offshore Platform Vibration-Distribution Structure

A new concept of vibration-distribution structure was advanced by the Bobal Oil Engineering and Design Company. It aimed to reduce the vibration of the off shore platform caused by flowing ice, earthquake and wave impact, phenomena which are very likely to take place in the Bobal area of China. The principal idea of vibration-distribution structure is to divide the main column of the platform into an inner tube and an outer tube. The outer tube is connected to the legs and pontoons by braces. The inner tube, which supports to Platform deck, is connected with the outer tube at the bottom. Both of them are either connected or disconnected at the position near the water line. For evaluating the effect of vibration reduction of such a structure, tests were carried out on a steel model. The loads of flowing ice, earthquake and waves were simulated by concentrated random forces applied on defferent points of the model. The tests were carried out in air and in water separately. The effect of vibration reduction was evaluated by the transfer function of the vibration responses at the measured points and represented by a dimensionless factor dependent on frequency only. It was shown by the tests that the vibration-distribution stucture is fairly effective in deducting the vibration of the platform.