Abstract:
The problem of wave radiation from concentric cylinders with porous ring plates for a given motion is investigated based on the framework of the linear potential flow theory. The concentric cylinders are subjected to radiation forces under the action of earthquakes, and their impact on structural safety cannot be ignored. The seismic action is simplified as simple harmonic oscillations, and its wave radiation response in the frequency domain is discussed. The flow field is divided into two regions, i.e., inner and outer regions, and the unknown coefficients in the radiation velocity potentials of the two regions are solved using the regions matching method. Using the radiation velocity potential of the inner and outer regions, the expressions for the calculation of the added masses, damping coefficients and radiation forces of the inner and outer cylinders have been developed. Based on this analytical theory, the effects of the permeability and depth of submergence of the dual ring plates, and water depth on the radiation response of the concentric cylinders are explored. The results show that the radiation forces of the inner and outer cylinders are influenced by the permeability and submergence depth of the ring plates and are related to the dimensionless wave number, whereas the decrease in the water depth increases the inner cylinder radiation force over the entire wave number interval. The analytical model and computational results in this paper can provide a basis for the seismic analysis of this type of structure.