海洋立管湿模态振动分析

针对海洋立管的湿模态振动问题，对立管固有频率以及各阶模态的相应振型展开了研究。阐述了模态概念与 模态分析的意义，运用ANSYS Workbench 中的Acoustic Extension 分析模块对海洋立管进行了湿模态振动分析，描述 了湿模态建模方法与技巧，得到12 阶固有频率与振型。通过与12 阶干模态分析结果进行对比，得出两者的区别，表 明了湿模态分析在做水下结构振动研究中的不可替代性。通过对立管结构进行优化，计算优化后的结构振动特性，得 到的优化结果，证明了优化的可行性。模态分析为研究结构的振动特性、优化结构设计提供了一定的依据，为防止结 构的共振提供了一定的参考。

An Analysis of the Wet Modal Vibration of Marine Riser

To solve the problems of the wet modal vibration of marine riser，we studied the natural frequency of the riser and the corresponding vibration modes. Using Acoustic Extension module of ANSYS Workbench，we analyzed the wet modal vibration of the marine riser，described the wet modal modeling methods and techniques，and obtained 12 natural frequencies and modes. By comparing with the 12 dry modal analysis，we found the differences between the two，which indicates that the wet modal analysis is irreplaceable in doing underwater research in structural vibration. By calculating the vibration characteristics of the optimized structure，we demonstrated the feasibility of optimization. Modal analysis provides a certain basis for the study of the vibration characteristics and the optimizing of structure，and a certain reference for preventing structure resonance.