civil Engineering Laboratory, Port Hueneme , California 

 Mooring Dynamics Seminar, January 10-11, 19 80 



THE RESPONSE OF MOORED FLOATING PLATFORMS TO OCEAN WAVES 



by 



J. R. PAULLING 

 Professor 

 Department of Naval Architecture 

 University of California 

 Berkeley, California 

 U.S.A. 



I . INTRODUCTION 



The principal loads which are exerted on a floating structure 

 by the sea depend on the relative motion between water and platform, 

 thus, both the motion of the sea and the motion of the platform 

 must be known in order to completely determine these fluid forces. 

 Since the motion of the platform constitutes its response to the 

 total external force system, it is seen that simultaneous solutions 

 to the loads and motions problems must, in general, be performed. 

 In addition to the fluid loads from I'/aves, currents and platform 

 motion, there are additional forces from external phenomena such 

 as wind and those which result from the mooring or positioning 

 system which is used to maintain the platform in its mean position. 



The hydrodynamic forces caused by wave and platform motion, 

 in general, have a complex dependence on the platform geometry and 

 on the motions of fluid and platform. In order to develop a 

 practical procedure for estimating these forces, it is invariably 

 necessary to make some retreat from reality. The usual simplifying 

 assumptions in this regard involve restrictions to either special 

 geometric configurations of the platform or restrictions on the 

 amplitudes of the fluid and platform motions. In the former cate- 

 gory, one procedure has been developed which assumes that the 

 platform configuration consists of a space frame assembly of slender 

 cylindrical members. A second widely used procedure is restricted 

 to platforms whose main elements consist of one or more slender 

 ship-like hulls floating either at the water surface or submerged. 



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