Computing of added mass influence on natural frequency of the underwater structure with numerical, analytical and experimental solution

It is obvious that the natural frequencies of a submerged structure are less than those of in vacuum and these are due to the effect of added mass of water to the structure.for marine structures, fluid inertial (added mass) effects cannot be neglected. This paper focuses on the experimental, analytical and numerical solution of natural frequencies of submerged stiffened plate. The analytical solution based on the deflection equation of submerged stiffened plate, Laplace’s equation and Rayleigh's method in vibration analysis.Considering small oscillations induced by the plate vibration in the incompressible and inviscid fluid.The velocity potential and Bernoulli’s equation are adopted to express the fluid pressure acting on the structure. The natural frequencies of the stiffened plate are obtained practically by using Fast Fourier Transformation functions (FFT) in experimental analysis. Experimental results demonstrate the validity of numerical and analytical solution and results.the experimental results validate the derived formulation for natural frequency of plate vibrate underwater.