Study on nonlinear dynamic response characteristics of modularized floating structure

The resonance effect induced by the nonlinear coupling of motions is an important consideration factor for the design of offshore floating structures. An investigation of the nonlinear dynamic response characteristics of modularized floating structure was conducted. Firstly, considering the influence of motion on the restoring force coefficients and buoyancy of floating module, the nonlinear dynamic model of single box-type floating module was built up. A wave flume experiment was then conducted in order to validate the reliability of this numerical model. Secondly, based on the rigid module-flexible connector (RMFC) model, a nonlinear generalized dynamic model for the modularized floating structure was established. Finally, the dynamic characteristics of the two-module floating structure were investigated by utilizing this numerical model verified by the experiment. The mechanism of motion instability was revealed and the solution methods for this motion instability issue were explored. The numerical results indicate that an appropriate transversal or vertical stiffness setting of connectors can effectively improve the instability of roll motion caused by the parametric resonance. © 2024 Central South University. All rights reserved.