Byoung Wan Kim

Numerical Study on the Hydroelastic Response of the Very Large floating Structure Considering Sea-Bottom Topography

A numerical method is developed for the hydroelastic response of the Very Large Floating Structure considering the sea-bottom topography. The sea-bottom effects on the hydroelastic response of the floating structure is studied. The sea-bottom topography should be considered when the floating structure is constructed near the shore. To investigate the sea-bottom effects, four different sea-bottom topographies are considered in this study. finite-element method based on the variational formulation is used in the fluid domain, The pontoon-type floating structure is modeled as the Kirchhoff plate. The mode superposition method is adopted for the hydroelastic behavior of the floating structure.

An efficient linearised dynamic analysis method for structural safety design of J-lay and S-lay pipeline installation

ABSTRACT In this paper, we propose an efficient linearised dynamic analysis method for structural safety design of J-lay and S-lay pipeline installation. By utilising finite element method and minimum energy principle, time domain equation of motion for pipeline is formulated. For efficient analysis, linearised beam element is utilised along with the equilibrium state of catenary and pretension due to its own weight to retain analysis accuracy. The efficiency and accuracy of the proposed method are compared with the former developed nonlinear method based on the catenary element which considers axial, bending and torsional stiffness. Numerical examples of J-lay and S-lay pipeline installation are introduced to demonstrate the developed method. Accuracy is verified by analysing maximum and root mean square values of bending moment and tension. By comparing computational costs, efficiency is also shown. Furthermore, discussion on the applicability of the proposed method for structural safety design is made.

Experimental Study of Water Impact Loads on Symmetric and Asymmetric Wedges

In the present study, the water impact loads on two-dimensional symmetric and asymmetric wedges were mainly studied. The impact pressure and force were measured during a vertical drop of the symmetric and asymmetric wedges. The measured pressure was compared with analytic solutions. The measured force at a local area of the wedge was compared with the integrated pressures and analytic solutions. Some findings on symmetric and asymmetrical wedge drops are presented, and the reliability of the force sensor used for the measurement of the local impact force is discussed.