Vibration of ships with special reference to shearing vibration¹

Article type: Research Article

Authors: Kumai, Toyoji^{; *}

Affiliations: Kyushu University, Fukuoka, Japan

Note: [1] Paper read at the Spring Meetings of the Society of Naval Architects of Japan, on the 14th May, 1956.

Note: [*] Member of the Society of Naval Architects of Japan.

Abstract: Some investigations into the flexural vibrations of ships’ hulls have been carried out. The author points out that such higher modes of hull vibration as are resonant with the propeller blade force excited through hydrodynamic action is considered as shearing vibration. The vibration profiles of the higher modes of hull vibration for certain assumed distributions of shear rigidity and of mass are calculated based on shearing vibration. Also, the natural frequencies of the fundamental mode to the eight-node mode of the vertical vibration of a cargo vessel, for example, are calculated based on shearing vibration taking the corrections for bending moment and rotatory inertia of the hull section into account. To obtain a simple method for the estimation of the natural frequencies of hull vibration including the higher modes in the initial design, stage an empirical formula based on shearing vibration is presented. The empirical factors of the formula are determined based on data which have been supplied to the author by the leading shipbuilders in Japan.

DOI: 10.3233/ISP-1957-43205

Journal: International Shipbuilding Progress, vol. 4, no. 32, pp. 220-228, 1957