方钢隔振结构对结构噪声隔离作用的理论分析与试验

  目的  研究采用阻振结构环路降低甲板结构平均振级、阻隔甲板结构低频振动向外传递的可行性。  方法  采用数值预报方法，分析阻振结构环路形式及截面参数对甲板及其邻近舱壁结构低频振动传递的影响。通过对比得出阻振效果较佳的阻振结构环路形式。在此基础上，开展阻振环路截面参数化研究，提出较优的甲板结构低频减振设计方案。  结果  研究表明：当阻振结构增重不超过主机舱总质量的5%时，同等质量的矩形多级阻振结构环路相对于其他环路形式具有更好的阻振效果；针对宽度不小于50 mm的阻振结构，当高度选择500 mm这一相对较优值时，选择宽度相对较小的阻振空心方钢，对降低甲板及邻近的舱壁结构平均振级的效果更好。  结论  研究结果为海洋平台甲板结构低频隔振设计提供了新思路。

Analysis and experimental research on the role of quadrate steel beam in isolating vibration wave

  Objectives  This paper studies the feasibility of the vibration isolation structure loop which is used to reduce the average vibration level of deck structures and to block the transmission of low-frequency vibration of deck structures.  Methods  The influence of forms and section parameters of vibration isolation structure loop on the low-frequency vibration transmission of deck and its adjacent bulkhead structure is explored by using numerical prediction method. By comparison, the form of vibration isolation structure loop with better vibration isolation effect is obtained. On this basis, the section parameterization of vibration isolation structure loop is carried out, and a better design scheme of deck structure with low-frequency vibration isolation is proposed.   Results   The results show that when the vibration isolation structure increases the total weight of the main engine room by no more than 5%, a rectangular multi-stage vibration isolation structure loop with the same mass has a better vibration isolation effect than other vibration isolation structure loops. For vibration isolation structures with a width of not less than 50 mm, when 500 mm is selected as a relatively optimum height and the relatively narrow hollow square steel is selected, the effect of reducing the average vibration level of deck and adjacent bulkhead structure is improved.   Conclusions  This research provides new insight relating to the design of low-frequency vibration isolation of the deck structures on offshore platforms.