• Journal of Advanced Marine Engineering and Technology
• /
• v.39 no.9
• /
• pp.903-910
• /
• 2015

The purpose of this research is to develop a full-spectral fatigue analysis program, based on rigid-body ship motion analysis, in order to perform a full-spectral fatigue analysis that considers hydroelasticity effects. To gain credibility, fatigue analysis results of two ship types, performed by the developed program, were compared with those of a classification society, and it was found that both are identical. Full-spectral fatigue analysis considering hydroelasticity effects would be developed in further studies by including flexible-body ship motion analysis results and by supplementing the developed program with a wide-band fatigue damage model.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2000.04a
• /
• pp.18-22
• /
• 2000

This paper is transient motions of a very large floating structure subjected to dynamic load induced by wave. A time domain method is applied to the hydroelasticity problems for this purpose. The method is based on source-dipole and FEM scheme and on Newmark $\beta$ method to pursuit time step process taking advantage of the memory effect. The present method is appied to hydroelastic response analysis in regular waves and impact responses due to dropping aircraft.

• Journal of the Society of Naval Architects of Korea
• /
• v.37 no.4
• /
• pp.75-81
• /
• 2000

Very large floating structures have rather small motion characteristics except their ends, where the motions become much larger due to the elastic motion of the structure. This paper presents the numerical predictions of hydroelastic behaviors of VLFS in irregular waves. To predict motion responses of structure in irregular waves, the source-dipole distribution method and finite element method is used.

• Journal of the Society of Naval Architects of Korea
• /
• v.36 no.4
• /
• pp.64-76
• /
• 1999

In this paper hydroelastic experimental techniques of very large floating offshore structures are suggested based on the model test carried out in the UOU Ocean Engineering Wide Tank. The prototype is a box-shaped floating structure with length of 300m, breadth of 60m, depth of 2m and draft of 0.5m and longitudinal bending rigidity as $4.87{\times}10^{10}kgm^2$. The scale ratio is 1/42.857. The model is realized by aluminum square pipes with the section dimension of $20mm{\times}20mm$. The numbers of longitudinal and transverse pipes are 7 and 35 respectively. Heave motions at selected points are measured with potentiometers and bending moments with strain gages.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2006.06a
• /
• pp.53-54
• /
• 2006

Experimental analyses on the Hydroelastic Flow-Structure Interactions on pulsed impinged jet is measured with the FSIMS(Flow-Structure Interaction Measurement System. The nozzle diameter is D=15mm and two major experiments have been carried out for the cases of the distance between the nozzle tip to the elastic wall is 6.0. The pulsed jets were controlled by a solenoid valve and were impinged onto an elastic plate (material: silicon, diameter: 350mm, thickness: 0.5mm, hardness: 15). The Reynolds numbers were 20,000 and 24,000 when the jets were impinged with the volume velocities. The results showed that the elastic plate moved slightly to the opposite direction of the jet direction at the time of valve opening. It has been shown that the vortices travelling over the surface of the wall made the elastic wall distorted locally due to a vector forces between rotating forces of the vortex and a newly-incoming flow.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2001.10a
• /
• pp.196-201
• /
• 2001

Very Large Floating Structures have been planned for effective utilization of ocean space in recent years. The VLFS usually has a control tower to guide airplane securely. This paper present an effective method for calculating the wave induced hydroelastic responses of VLFS considering the effect of control tower-shapes. The source and dipole distribution method is used to calculate the hydrodynamic loads and equation of motion is derived by considering the static and dynamic coupling effects from different segments of the plate. The rigidity matrix for VLFS is formulated by finite element method using a plate theory. The calculated results for VLFS with a control tower are compared with those for VLFS without a control tower.

• Journal of Ocean Engineering and Technology
• /
• v.19 no.4 s.65
• /
• pp.1-8
• /
• 2005

A nonlinear time-domain strip theory for vertical wave loads and ship responses is to be investigated. The hydrodynamic memory effect is approximated by a higher order differential equation without convolution. The ship is modeled as a non-uniform Timoshenko beam. Numerical calculations are presented for the S175 Containership translating with the forward speed in regular waves. The approach described in this paper can be used in evaluating ship motions and wave loads in extreme wave conditions and validating nonlinear phenomena in ship design.

• Journal of Ocean Engineering and Technology
• /
• v.16 no.2
• /
• pp.32-37
• /
• 2002

Very Large Floating Structures have been planned for effective utilization of ocean space in recent years. The nonerctangular VLFS usually has a control tower to guide airplane securely. This paper presents an effective method for calculating the wave induced hydroelastic responses of VLFS considering the effect of control tower-shapes. The source and dipole distribution method is used to calculate the plate. The rigidity matrix for VLFS is formulated by finite element method using a plate theory. The calculated results for nonerctangular VLFS with a control tower are compared with those for VLFS without a control tower.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.1
• /
• pp.195-201
• /
• 2006

The wave load and its influence on the response of offshore structure have been well investigated through the statistical approach based on the linear theory. The linear approach has a limitation to apply the extreme condition such as freak wave, which corresponds to extreme value of wave spectrum. The main topic of present study is to develop an efficient numerical method to predict wave load induced by extreme wave. As a numerical method, finite element method based on variational principle is adopted. The frequency-focusing method is applied to generate the extreme wave in the numerical wave tank. The wave load on the bottom mounted vertical cylinder is investigated. The hydroelastic response of the vertical cylinder is also investigated so as to compare the wave loads with the rigid body case in the extreme wave condition.

• Journal of Navigation and Port Research
• /
• v.31 no.1 s.117
• /
• pp.21-27
• /
• 2007

The wave load and its influence on the response of offshore structure have been well investigated through the statistical approach based on the linear theory. The linear approach has a limitation to apply the extreme condition such as extreme wave, which corresponds to extreme value of wave spectrum. The main topic of present study is to develop an efficient numerical method to predict wave load induced by extreme wave. As a numerical method, finite element method based on variational principle is adopted. The frequency-focusing method is applied to generate the extreme wave in the numerical wave tank. The wave load on the bottom mounted vertical cylinder is investigated. The hydroelastic response of the vertical cylinder is also investigated so as to compare the wave loads with the rigid body case in the extreme wave condition.