2004 Volume 20 Pages 1277-1282
This paper deals with the characteristics of combination resonance for submerged floating structure. The combination resonance takes place in a vibratory system having multiple degrees-of-freedom and under parametric excitation. In this study, it is assumed that the floating structure is moored by some tension legs and located in the water between seabed and water surface. Due to such a structural form, there is much possibility that complicated dynamic phenomena like parametric excitation take place. The parametric excitation is caused by the time-varying tension force of tension legs. The time-varying tension force arises when some dynamic loads such as regular waves act on the floating body and the body moves in the water. In this paper, analytical studies are carried out to confirm the possibility of the occurrence of unstable motions by introducing Mathieu equations and effects of tension leg arrangements on the combination resonance characteristics are investigated in particular.
