The main point of the
present work is an investigation into effects of the wave form on the ship
structural analysis.That is the bending moment of a ship may appear to have
different results according to the different wave profiles.This analysis will
show us the affected parameters of the ship structure based on wave forms
In addition, an excel
data sheet will be constructed for general use with selected wave forms based
on the variation of the ship lenght.This will be done by new developing
parameters.These parameters will facilitate the preparation of a
non-dimentionalized excel work table.
The first key point
with the starting of the project is gathering important and qualified,
trustable information about ship
structures, wave form profiles & their deterministic effect on the
structural analysis.This approach will create the oppurtunity to perform a
better analysis and obtain good results.
On the other hand, the
usage of the different wave forms will provide guidance to develop applications
for bending moment examinations.Also this knowledge base will help the
selection of the wave profile for other computations.
The main part of this
investigation is making effective and satisfactory calculations on the selected
ship type structural analysis on an excel work sheet. To get better results,
all of the specified knowledge about
wave profiles and their critical parametric effects will be applied to
the ship structural analysis.After obtaining the shear force and bending moment
results as a variable of the wave forms, they will be compared in order to
choose the most effective wave form analysis.
calculations will be performed to determine the wave form and the ship type
between the selected ship length ranges.Accordingly, the ship structural form
will be determined as a design tool.It is intended that the procedure will
provide the bending moment results for the selected ship length ranges.The main
parameters will be the ship’s length, depth and its displacement together with
the wave profile and height.
My dissertation investigation is making a parametric study of wave profile selection on the quasi – static calculation of the wave bending moment of ships.In that case the examinations will be done about the differences in the results of force and moment balances, which are the main conclusions after the buoyancy dispersion, depending on their wave alignments and their wave profiles stated by Class institutions.Nowadays, shipbuilding industry and manufacturing elements are seen to be designed more uniformly and durable steel hull forms in the design stages comparing with past, depend on the work more regularly and efficiently with the development of the technology.
The process of validation of the designs of the variable Class institutions in eligibility with their different rules, expectations and desired criteria limits are exposing great developments and progress records. Nevertheless, there are some variations in the longitudinal strength analysis, which is still the most important part of the shipbuilding process. These variations are wide open, but their results are limiting with some basis.The most key point while making longitudinal strength analysis is being on attent to the equality of the weight distrubition, buoyancy distribution, shear forces and bending moments. Depending on these balances, a determination of the suitability of a ship for the construction condition is made and the approval can be taken to switch to the next stage of the design phase. However, moment and force balances, which are the main elements there, are determined in terms of weight distributions based on buoyancy distributions on the basis of the hypothetical dimensions of the waves that can affect the ship. The weight distribution in this area is based on hypothetical formulas based on ship mid-section.Buoyancy distributions are investigating under two main headings, wave crest and wave trough, by studying the wave structures and dimensions that might come to the ships depending on certain limitations in various class organizations. Depending on these distributions, it will not be possible to give a start for constructing the ship, unless the force and moment balances obtained are within certain limits, and this is a sign that there are some problems in the previous stages in the design phase. However, there are more dangerous and life-threatening risks to the taking construction approval for the ship by changing any consequences of the analysis. It is quite important that such a situation does not happen.In this dissertation investigation,the making of a parametric study of wave form determination on the quasi – static measurements of the wave bending moment of ships.In that case the examinations will show the possible differences in the result datas of loads and moment balances, which are the main summarizing after the buoyancy dispersion, based on their wave placements and their wave structural form defined by Class organizations.Structural strength can be explained as the protection of integrity, without structural deformation, under preloaded loading conditions against all internal and external forces. But there is no form can be protected against all the forces without distorting its shape. For example, when a soft metal pipe is pulled from both ends by machines, the length will increase after a while and we will examine it from the center line its thickness get thinner or if we press the sides upwards after a certain period of time, its middle will fall down. There are a lot of examples like this and this. 7There are two important points in this resistance against the forces.1.The portion that reaches to the elastic deformation and corresponds to the flow point.2.The extent of the flow limit that also specified as the stress. 7The structural strength of a ship in engineering terminology is determined by two important conditions I have mentioned. In order to be safe against specified loading conditions and against all forces and loads that may be externally influenced, the self-tension of the build must remain under yield stress. 7 This ratio is limited to about 6% or even less.The ship is a complex building with a lot of structural details. Based on the static assumption of longitudinal strength (structural strength) of the ship in the loading condition, the calculation of the cross-sectional shear force and bending moment distributions of the loads acting on the ship in the direction of the acceptance of the structural integrity as a beam and the preparation of the section in such a way as to be based on the case where the stress is less than the yield limit, all of the examinations for determining the problems to be caused due to the deterioration which may be happening possibility on the sectional surfaces can be determined as the strength of the ship. 5 Nonetheless, the possible analysis problems can be solved by making some changes in weight distribution or the mid ship sectional strength module. 2Generally, the analysis are done while the movement of the ship is very slow in the case of calm water and very long period fluctuations.Therefore, the dynamic loads that can occur due to their level that can be neglected. In this direction, loads can be assumed as static assumptions while longitudinal strength is considered. 7Loads affecting the ship’s structure can be examined in 2 main roads depending on the load source and frequency.
The two most important classifications that affect the structural form of the ship and depend on freight sources are as follows.Structural weights mentioned here can be described as steel vessel weight of the ship, main and auxiliary machines, outfitting weights, cargo loads and ballasts.
Hydrostatic calculations after the determination of the ship form and a continuously available qualification as determined by Bon Jean Curves and structural weight. 5
There are still two more load types which are depending on the situation.These loads are the loads that can occur during a landing from the ship,or when sitting on the ground on land, but they need to be inspected when necessary.Separately, the cooling that exists in vessels working on cold glacier cuts, or arthritis or antarctica, causes extra strain. Practically, these loads do not have much maintenance unless they constitute an extra case They do
not need to be taken into much attention. The classification of the loads on the ship according to their frequencies can be examined separately as follows. They are loads that are dependent on ship’s weight in long-term changes such as loading or unloading at ports, fuel consumption during cruising and consumption in water tanks. The sudden change
in these loads can already be offset by ballast intake.Also including force in the load category depends on buoyancy distribution on calm sea water.