Summary: | 碩士 === 國立成功大學 === 造船工程學系 === 82 === The purpose of this study is to investigate the static and
dynamic structuralresponses of the small-waterplane-area twin-
hull(SWATH)ship under harmonic wave excitation.The study is
carried out by means of finite element analysis,in which the
program "MSC/NASTRAN" and the pre-post processor "MSC/XL" are
used. In the static analysis,three kinds of loading conditions,
1.still water condition;2.head seas condition;3.beam seas
condition are considered.In order to determine the entire
structural responses and the typical local stress in critical
location of the SWATH ship,a 3-D coarse mesh finite element
model representing of the entire vesel and 2-D fine mesh finite
element models resprenting the the bulkhead and web frame are
establishsd.The purpose of 3-D finite element model is used to
get the overall response of the vessel based on its caargo and
seaway loadings and showing in the form of stresses and
displacements.Moreover,the nodal displacements denote the
boundary conditions for the subsequent 2-D finite element
analysis.Based on the 2-D finite element analysis,the detail
local stresses analysis obtained. In the dynamic analysis,the
free vibration analysis of the SWATH ship on still water
surface and the dynamic responses of the SWATH ship with 20
knots forward speed in beam seas and head seas are considered.
The coupled responses of rigid-body motions and elastic
vibrations of the SWATH ship due to wave exciting forces are
determined. The analytical approach for determing the motion
and wave loads is based on the linear seakeeping theory and the
assumption of the harmonic wave excitation.
|