Abstract
This paper studies a methodology for the active nonlinear control of dynamically loaded flexible structures. The control method is based on nonlinear optimal control, using an indicial formulation of tensor algebra and state feedback control. The state equations and the control forces are expressed in a polynomial form. General polynomial representations of the nonlinear control law are obtained up to the fifth order. This methodology is applied to control the nonlinear vibrations of a fixed offshore structure using a simplified model. The resulting equation of motion is strongly nonlinear, with quadratic and cubic nonlinearities. The response of the system subjected to ocean waves and ground acceleration is studied and the effectiveness of the control system is discussed. Numerical results indicate that the control algorithm adopted can be efficient for nonlinear systems, chiefly in the presence of strong nonlinearities.
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Pinto, O.C., Gonçalves, P.B. Nonlinear optimal control of flexible structures: application to a fixed offshore structure. Mar. Syst. Ocean Technol. 1, 127–136 (2005). https://doi.org/10.1007/BF03449204
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DOI: https://doi.org/10.1007/BF03449204