海洋平台局部振动模态分析

应用有限元分析软件,建立了W12 1上压缩机局部安装平台的有限元模型,并根据压缩机安装平台局部振动响应的周期与压缩机振动周期呈现较强一致性的现场测试结果,对模型进行了合理的简化。利用此有限元模型进行了振动模态分析。结果表明,平台结构的不合理所造成的平台局部刚度不足引起平台模态振动畸变,是引起平台振动过大的主要原因。增加平台横梁刚度和改变平台底部斜撑位置等措施能消除模态振动畸变,有效地抑制平台过大的振动。增加平台横梁刚度抑振措施适合已建平台的改造,而改变平台底部斜撑位置的抑振措施只适合在建平台。

Vibration modal analysis of local offshore platforms

A modal of the compressor installation local platform of W12-1 was created using finite element software. The experimental results show that the vibration of the compressor installation local platform is caused by the working of the compressors. The modal was reduced due to the consistent vibratory frequency. The modal analysis of W12-1 local offshore platform was carried out using finite element analysis. The results indicate that the insufficient local stiffness of the compressor installation platform is the reason of vibration modal distortion. The methods for removing the distortion were proposed by means of increasing the stiffness of beam and changing the position of the inclined support. The computational results show that the vibration can be restrained effectively. The method for increasing the stiffness of beam can be used to reform the platform that has been built and the method for changing the position of the inclined support can only be used in the platform that is going to be built. That is to say, the second method can be used to direct the dynamic design of offshore platform.