주변 유체와 연성된 수중 구조물의 진동분석을 위한 스펙트럼 요소법

To design a spacer grid for protecting underwater structures consisting of cylinders against sudden external loads, it is necessary to perform a numerical analysis on the coupling system considering the structural vibration and surrounding fluids. The structural vibration of cylinders coupled with viscous fluid is predicted by using the spectral element method (SEM). Scattering waves induced by traveling plane waves are calculated and utilized to investigate the pressure forces of structures, and the transfer function for the flexural vibration and pressure amplitudes of plane wave is calculated. The finite element method (FEM) is used to verify the numerical results obtained using the SEM. The amplitudes of the added mass of each cylinder are dependent on the gap between surrounding fluids and adjacent structures. When the input frequency of traveling waves is increased, the pressure fields become significantly more complicated. When the number of cylinders is increased, the transfer function at the specific frequency ranges show overlapping resonance modes. The proposed numerical method can be used to save the computing time and improve the accuracy of the numerical analysis technique for studying the vibration of underwater structures.