Naslov
Comparative study of hydroelastic response of large container ships determined by different formulations of restoring stiffness in FEM technique

Autori
Hadžić, Neven

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, ostalo

Skup
Suvremene metode projektiranja ultra velikih brodova – Prikaz rezultata znanstveno- istraživačkog projekta EU FP7 TULCS (Tools for Ultra Large Container Ships)

Mjesto i datum
Zagreb, Hrvatska, 30.05.2014

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
hydroelasticity; restoring stiffness; finite element method; barge response

Sažetak
Two different restoring stiffness formulations for ship hydroelastic analysis are considered, i.e. consistent one, as an extension of the ordinary restoring stiffness in ship rigid body motion in waves, and another structurally oriented one which comprises geometric stiffness with ship stress distribution in calm sea. In order to increase the accuracy of the stiffness coefficients in modal analysis the finite element technique is employed. Triangular and rectangular finite elements are worked out for panels of wetted surface and structural members, i.e. plates and beams. The geometric stiffness matrix consists of three parts, one related to plate deflection, well- known in buckling analysis, and two additional for membrane displacements, which complete expression for ship stability. For all three parts the same shape functions of membrane displacements are used due to reason of simplicity. A special software for generation of restoring stiffness is developed and incorporated in package for ship hydroelastic analysis. The hydroelastic response of a thin- walled barge is determined by employing the consistent restoring stiffness in two variants, i.e. with distributed structural mass and lumped masses, and the complete restoring stiffness. The response includes the transfer functions of rigid body and elastic modes, and those for vertical, horizontal and torsional sectional forces. Moderate differences of three sets of calculations are noticed in a narrow region of the lower frequency range. Some valuable conclusions based on that numerical test are drawn.

Izvorni jezik
Engleski

Znanstvena područja
Brodogradnja

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