A simplified model for hydroelasticity of containerships

In this work, a semi-analytic method has been developed to perform the hydroelasticity analysis of containerships. For the solution of the hydrodynamic problem, a time-domain method is developed based on impulse response function (IRF); however, for the solution of the structural responses, modal superposition technique is used assuming the ship is based on Euler–Bernoulli beam theory. The time-domain amplitude of the displacements and velocities corresponding to several modes is then determined using a semi-analytic approach using Duhamel integral technique. In this paper, the effect of structural flexibility in the calculation of structural displacement, shear force, and bending moment is studied. To check the efficiency and correctness of the proposed semi-analytic method, initially, the computed results are compared with published and experimental results for two container ships with different lengths. In the second phase, a comparative study has been made to check the effect of several physical and geometric parameters such as ship length, vessel speed, and wavelength to ship length ratio. It is seen from the comparative study that ship length, Froude number, wave to ship length ratio, etc. have a significant effect in the calculations of global bending moment, shear force. From the computed results, it may be concluded that the proposed semi-analytic approach is capable of generating results within an acceptable range of engineering accuracy with negligible computational effort, and thus, it can be a very useful tool for preliminary design load for larger vessels.