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distributed mass, in other words, the hydrodynamic forces on a VLFS is almost independent of the
draft of the structure.
2) In case of the very shallow draft condition, the numerical accuracy of 3-D SDM may get worse.
Practically speaking, it is not necessary to use finer mesh for the calculation, but it is better to adopt
the appropriate deeper draft to save the computational time.
3) The effectiveness of the zero draft assumption is verified w.r.t. not only the elastic deformation but
also the steady wave drifting forces.
References

Maeda H., Masuda K., Miyajima S. and Ikoma T. (1996). Hydroelastic Responses of Pontoon Type
Very Large Floating Offshore Structure. Proceeding of the 15th international conference on Offshore
Mechanics and Arctic Engineering ASME Vol.I,407-4 14
Kashiwagi M. (1998). A B-spline Galerkin scheme for calculating the hydroelastic response of a very
large floating structure in waves. Journal of Marine Science and Technology 3,3749
Ohmatsu S. (1998). Numerical calculation of hydroelastic behavior of pontoon type VLFS in waves.
Proceedings of the 1 7th International conference on Offshore Mechanics and Arctic Engineering
ASME CD-ROM OMAE98-4333
Kim J.W. and Ertekin R.C. (1998). An eigen function-expansion method for predicting hydroelastic
behavior of a hallow-draft VLFS. Second International Conference On Hydroelasticity in Marine
Technology (Hydroelasticity '98), 47-59
Nagata S., Yoshida H., Fujita T. and Isshiki H. (1997). THE ANALYSIS OF THE WAVE-INDUCED
RESPONSES OF AN ELASTIC FLOATING PLATE. Proceeding of the 16th international conference
on Offshore Mechanics and Arctic Engineering ASME Vol.VI, 163-178
Kim J.W. and Ertekin R.C. (2000). Hydroelastic Response of Mat-type VLFS: Effects of Non-Zero
Draft and Mass Assumptions. Conference Proceedings of OCEANS2000 MTSAEEE CD-ROM in
Session 53
Maeda H., Ikoma T. and Masuda K. (1998). Wave Drift Forces of a Very Large Flexible Floating
Structure. Proceedings of the 7th International Symposium on Practical Design of Ships and Mobile
Units ELSEVIER, 1037-1043
TABLE 1
PRINCIPAL PARTICULARS OF THE CALCULATION MODEL
Length of model (m) 1000
Width of model (m) 250
Draft of model fm) 2.5.8
Bending Stiffness per
Width (kgf/m2/m) 2x 10'O
-
*
Point 1(-500, 125) y
Incoming wave 4
Odeg.

f
60deg. / r 1 OOOm

Figure 2: Calculation points of vertical displacement and angle of incoming waves