Hydroelastic motions and drift forces of very large mobile offshore structure in waves

We propose a new concept of VLMOS, which is composed of slender beams and demi-hulls. The main topic of this paper is to understand the hydroelastic behavior of VLMOS. We have carried out the experiment and the calculation for the hydroelastic behavior of this structure. We conclude that the agreement between the experimental results and the numerical results is good. The strain of the transverse beam in the beam waves has a high peak, which should be lowered for the realistic design of this concept. It is found that drift forces are not significant except for the frequency of the resonance of the 2-nodes vibration mode. Summarizing the results obtained by the experiment and the computation, it is found that minimizing the 2-nodes vibration mode occurring at the transverse beam is a key to realizing this concept.