Wave Induced Forces and Motions of Tubular Structures 



waves using a platform model of triangular plan form to investigate 

 the predictability and linearity of motions and mooring tensions of a 

 composite structure consisting of a nunnber of cylindrical members. 

 Finally, experiments were made in random seas to test the applica- 

 bility of linear superposition. 



The arrangement of the model and experimental apparatus 

 is shown in Fig. 3. The model configuration shown Is typical of a 

 number of those tested, consisting of three base cylinders arranged 

 to form an equilateral triangle with three or more vertical legs 

 supporting the deck. An Important geometrical parameter studied 

 In these tests was the relative proportion of buoyant volume contained 

 In the vertical and horlzontcil legs. 



LEGS 



LEG 2 



X-AXIS 



LEG I 



Z-AXIS 



SURGE POTENTIOMETER SHEAVE 

 YAW RATE GYRO 



v\\\\\\^ \ \ >W\ 



IDLER 

 PULLEY, 



e 



X-AXIS 



DEAD-WEIGHT 

 ANCHORS 



PLATFORM J. 

 MODEL 



INSTRUMENT 



LEADS 



TO RECORDER 



TANK BOTTOM 



Fig. 3, Arrangement of experimental apparatus 



1101 



