Sticking Paint Replacement Films on Ship Hull Surfaced based on Lines of Curvature

2019 ◽  
Author(s):  
M Takezawa ◽  
K Matsuo
Keyword(s):  
Shape Optimization ◽  
Nonlinear Optimization ◽  
Thin Sheet ◽  
Ship Hull ◽  
Surface Shape ◽  
Bulk Carrier ◽  
B Spline ◽  
Original Surface ◽  
Lines Of Curvature ◽  
Curvature Lines

In this paper, we propose a new concept of using the paint replacement films covering a ship-hull surface instead of paint based on lines of curvature. Firstly, we correct the B-spline hull surface within the prescribed deviation from the original surface shape based on nonlinear optimization to smooth the flow of curvature lines. After shape optimization, we adjust the position and the number of curvature lines so that it becomes the surface developments suitable for applying to thin sheet films. Using our method, it is possible to stick the films on the hull surface with few wrinkles. Finally, we applied proposed techniques to a bow of a bulk carrier to demonstrate the effectiveness of our algorithms.

scholarly journals Development of Support System for Ship-Hull Plate Forming Using Laser Scanner

2021 ◽  
Vol 15 (3) ◽  
pp. 290-300
Author(s):  
Masahito Takezawa ◽  
◽  
Kohei Matsuo ◽  
Takahiro Ando
Keyword(s):  
Point Cloud ◽  
Laser Scanner ◽  
Target Surface ◽  
Ship Hull ◽  
B Spline ◽  
Spline Surface ◽  
Lines Of Curvature ◽  
Plate Shape ◽  
The Difference ◽  
Ship Hull Plate

In this study, we developed a new system that outputs the additional press work procedures necessary to obtain the desired ship-hull surface. This study is unique in terms of determining the additional press work procedures required according to the current plate shape at any work stage by measuring the plate shape using a laser scanner. In the proposed method, a B-spline surface is constructed from a point cloud measured using a laser scanner, and the current plate shape is analyzed based on differential geometry. Additional press lines are estimated based on the difference in the normal curvature along the lines of curvature between the designed target surface and the current surface. We demonstrated the effectiveness of our proposed method through experiments at a shipyard. The proposed system may be used to enhance the efficiency of press work and is expected to be an effective tool for training beginners in the future.

scholarly journals Оптимизация алюминиевой крышки люкового закрытия сухогрузного судна

2020 ◽  
Author(s):  
G.B. Kryzhevich ◽  
A.R. Filatov
Keyword(s):  
Shape Optimization ◽  
Parametric Optimization ◽  
Optimization Methods ◽  
Topological Optimization ◽  
Design And Technology ◽  
Bulk Carrier ◽  
Material Consumption ◽  
Considerable Decrease ◽  
Bulk Carriers ◽  
Cargo Transportation

Объектом исследования является крышка люкового закрытия сухогрузного судна, служащая для обеспечения непроницаемости грузовых помещений и перевозки на ней грузов и обеспечивающая безопасность сухогрузных судов и осуществляемой на них морской перевозки грузов. Большая материалоемкость крышек снижает экономическую эффективность судна, ведет к необходимости использования мощных и массогабаритных средств подъема крышек (для съемных люковых закрытий), либо поворота и передвижения крышек (для шарнирно-откидных закрытий). Целью статьи является существенное снижение материалоемкости крышек люкового закрытия за счет рационального выбора их материала и конструктивного оформления при одновременном обеспечении требуемого уровня их надежности. Параметрическая оптимизация традиционной стальной крышки люкового закрытия сухогрузного судна проекта RSD59 может привести к снижению ее массы не более чем на 15-17. Поэтому для достижения цели работы решается задача оптимизации конструкции алюминиевой крышки на основе комплексного подхода, состоящего в последовательном использовании топологических и параметрических оптимизационных методов и выполнении на последней стадии работы снижения уровня концентрации напряжений путем оптимизации формы узлов крышки. При этом на стадии выбора конструктивно-силовой схемы крышки применяются приёмы топологической оптимизации, на стадии выбора толщин и параметров силовых элементов способы параметрической оптимизации, а на стадии конструктивно-технологического оформления узлов методы оптимизации формы. Выполненные расчетные исследования привели к следующим основным результатам: к выявлению прогрессивных конструктивно-силовых схем и конструктивно-технологических решений, обеспечивающих значительное снижению массы крышек люковых закрытий при умеренных затратах на их изготовление к высоким оценкам эффективности использования современных алюминиевых сплавов для изготовления люковых закрытий, способствующим существенному снижению их материалоемкости (примерно двукратному и более по сравнению с использованием стали), улучшению условий их функционирования и проведения погрузочно-разгрузочных работ на сухогрузных судах к выводу об эффективности использования разработанных конструкторских решений для крышек люковых закрытий при создании перспективных сухогрузных судов.A bulk carrier hatch cover, which provides cargo compartments impermeability and cargo transportation on the cover, as well as safety of bulk carriers and sea cargo transportation in them, is studied. Cover high material consumption decreases vessel profitability, causes the necessity to use either powerful and mass-dimensional cover lifting devices (for removable hatch covers) or covers rotation and movement (for hinged covers). The purpose of this paper consists in considerable decrease of hatch cover material consumption through rational selection of covers material and design at provision of the required covers reliability level. Parametric optimization of a conventional steel cover of RSD59 project bulk carrier could result in cover mass decrease by more than 15 to 17. Therefore, to achieve the work purpose, a problem of aluminum cover structural optimization was solved based on a comprehensive approach that consisted in successive use of topologic and parametric optimization methods and decrease of the stress concentration level at the last step via cover assemblies shape optimization. At that topological optimization methods were applied at the stage of selecting cover structural arrangement parametric optimization methods were applied at the stage of selecting load-carrying elements thickness and parameters, and shape optimization methods were used at the stage of structural and technology design of assemblies. The performed calculation studies resulted in the following: revealing the advanced structural arrangements and design and technology solutions that provide considerable hatch covers mass decrease at reasonable costs for their manufacture high assessment of using advanced aluminum alloys for manufacturing hatch covers that promote considerable decrease of their material consumption (approximately up to twofold or greater in comparison with steel), improving conditions of cover functioning and handling operation in bulk carriers conclusion on effectiveness of using developed design solutions for hatch covers when creating prospective bulk carriers.

Structure Vibration Shape Optimization Based on Power Flow Response Analysis

2014 ◽  
Vol 490-491 ◽  
pp. 712-718
Author(s):  
Xue Bao Xia ◽  
Yang Xiang ◽  
Shao Wei Wu
Keyword(s):  
Shape Optimization ◽  
Mode Shape ◽  
Power Flow ◽  
Flow Analysis ◽  
Optimization Method ◽  
Weight Coefficient ◽  
Surface Shape ◽  
Response Analysis ◽  
Flow Response ◽  
Vibration Power Flow

Power flow analysis is a method to describe the dynamic behavior of structures by taking not only the amplitude of exciting force and velocity response into account, but also the phase between the two qualities. Shape optimization is an effective method to reduce vibration level. By choosing the vibration power flow as design objective, a shape optimization method of structure is presented. The structure surface is restructured with a series of mode shape superposition. By using genetic algorithm, the weight coefficient of each mode shape is optimized to get the best surface shape with minimum power flow response. Some examples are demonstrated to verify the efficiency and accuracy of the method.

scholarly journals Influence of curve fitting techniques on hydrostatic characteristics of ship

1970 ◽  
Vol 39 (2) ◽  
pp. 100-112
Author(s):  
Md Mashud Karim ◽  
Md Ashim Ali ◽  
Kho. Sahriar Iqbal
Keyword(s):  
Curve Fitting ◽  
Mechanical Engineering ◽  
Cubic Spline ◽  
Ship Hull ◽  
Least Square ◽  
Ship Stability ◽  
Hull Form ◽  
B Spline ◽  
Using Data ◽  
Table Data

This paper presents influence of curve fitting techniques on hydrostatic characteristics of marine vessels.  Three vessels having lengths of 32.16m, 70.0m and 25.6m are selected for this study. The hull geometries of these vessels are represented by three curve fitting techniques such as least square, cubic spline and B-spline methods. At first, hydrostatic characteristics of the vessels are calculated using data only available in offset table and then using more data generated by curve fitting techniques. Finally, results obtained by offset table data are compared to those by fitted data. It is seen that there are some influences of curve fitting technique on the hydrostatic characteristics of ship especially at lightly loaded condition. Keywords: Curve fitting technique, ship hull form, offset table, hydrostatic characteristics, ship stability, cross curve. doi:10.3329/jme.v39i2.1853 Journal of Mechanical Engineering, Vol. ME39, No. 2, Dec. 2008 100-112

Evolutionary Structural Shape Optimization Based on Adaptive FEM and Boundary Representation of B-Spline

2012 ◽  
Vol 562-564 ◽  
pp. 1575-1582
Author(s):  
Sheng Li Gu ◽  
Fu Ming Wang
Keyword(s):  
Shape Optimization ◽  
Boundary Representation ◽  
Structural Shape ◽  
B Spline ◽  
B Splines ◽  
Structural Shape Optimization ◽  
Evolutionary Structural Optimization ◽  
Design Variables ◽  
Adaptive Fem ◽  
Element Error

This paper presents a structural shape optimization algorithm based on the evolutionary structural optimization (ESO) method in conjunction with element error estimate and adaptive FEM. B-splines are used to describe the boundary of the design domain; the shape of these B-splines is governed by a set of master nodes which can be taken as the design variables. The optimal shape of the design boundary with constant stress is achieved iteratively by the movement and update of the position of the master nodes based on nodal stress leveling. The result quality, in terms of accuracy and efficiency, is tested and discussed with an analytical solution.

scholarly journals Shape Optimization Design for a Centrifuge Structure with Multi Topological Configurations Based on the B-Spline FCM and GCMMA

2020 ◽  
Vol 10 (2) ◽  
pp. 620
Author(s):  
Xinyao Li ◽  
Liangli He
Keyword(s):  
Shape Optimization ◽  
Optimization Design ◽  
Design Method ◽  
Von Mises Stress ◽  
Design Solution ◽  
Deformation And Failure ◽  
B Spline ◽  
Geotechnical Centrifuge ◽  
Final Configuration ◽  
Deep Groove

The geotechnical centrifuge applied in various geotechnical engineering fields provides physical data for investigating mechanisms of deformation and failure and for validating analytical and numerical methods by simulating and studying the geotechnical problems. The basket, as one of the important components used to place the inspection model of centrifugal test, is designed to withstand complex loads. This paper presents an optimization design method for the basket based on the weighted B-Spline Finite Cell Method (FCM) and the globally-convergent method of moving asymptotes (GCMMA). In order to obtain a superior design solution, four topological configurations, i.e., original single web, porous dual web, open deep groove dual web, and connected closed dual web, are investigated and optimized. The mass is selected as the optimization objective, while key shape parameters and stress are regarded as design variables and the constraint, respectively. By optimization, the final masses of the four configurations are reduced greatly compared with the initial configurations, where the greatest weight loss, in case 4, is 10.6%. This indicates that the weighted B-Spline FCM and GCMMA can be well applied for shape optimization of structure in engineering design. In contrast to the final single web adopted in the traditional basket design in case 1, the final configuration in case 4, i.e., connected closed dual web, has the least mass. The final mass is reduced by 133.38 kg when the centrifuge strength requirement is met. Therefore, the final configuration in case 4, where the maximum von-Mises stress is 398.72MPa and mass is 781.82 kg, is superior to the three other configurations.

Sign in / Sign up

Export Citation Format

Share Document