An efficient method to compute the seismic response of an offshore platform in still water is presented. The structure is modelled by a three-dimensional space frame with lumped parameters and the dynamic response is determined by the mode-superposition method. Both the effects of the nonlinear drag force and the mode-damping coupling are also taken into account. The random nonlinear drag force is linearized by the method of the least square in statistical sense, and the mode-damping coupling is uncoupled by use of the concept of the generalized complex damping. As a consequence some important spectral bandwidths for all vibrational modes can be derived simply in terms of the generalized complex damping ratios and fhe generalized coordinates at resonances.
Generalized complex damping and spectral bandwidths for seismic responses of offshore platforms
International Shipbuilding Progress ; 34 , 389 ; 2-11
1987-01-01
10 pages
Article (Journal)
Electronic Resource
English
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