A Comprehensive Line-Heating Algorithm for Automatic Formation of Curved Shell Plates

Line heating is a method used in the production of highly curved plates in the shipbuilding process. Line-heating process is generally regarded as one of the outdated technologies in the modernized and automated shipbuilding process. No piece of information in the line-heating process is either quantified or computerized. These drawbacks have restricted the automation of line-heating process and, as a result, the entire shipbuilding process. Therefore, a new automated line-heating process based on quantitative and computerized heating information has been sought. This paper describes a comprehensive algorithm for an automated line-heating process. By focusing on the overview of the complete algorithm, this paper integrates the components of the algorithm that have been separately published by the authors. The overall procedure of the automated line-heating process, including shell piece modeling, shell development, cylindrical approximation for curved plates, computation of heating information, and measurement and surface comparison, is discussed. The comprehensive algorithm is adjustable for different heat sources and measuring methods, without incurring fundamental changes in algorithm. The proposed line-heating algorithm has been implemented and transferred to some shipyards for customized applications. Simulation of automated line-heating facility

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An Embedded Prototype for a Distributed and Automated Line Heating System

Journal of Ship Production ◽

10.5957/jsp.2009.25.4.182 ◽

2009 ◽

Vol 25 (04) ◽

pp. 182-190 ◽

Cited By ~ 1

Author(s):

Jackyou Noh ◽

Jong Gye Shin ◽

Kwang Hee Ko ◽

Jae An Chun

Keyword(s):

Robot Control ◽

Heating System ◽

Heating Process ◽

Current Line ◽

Line Heating ◽

Design Data ◽

Heating Systems ◽

Network Information ◽

Automated Process ◽

Automated Line

Automated line heating systems have been developed based on stand-alone operation with no consideration of the extensibility and maintainability. In the line heating shop, many of the line heating works are performed simultaneously; therefore, a collaborative and simultaneous automated line heating system is needed. In order to develop such a new line heating system, the current line heating process was analyzed, and then a distributed and automated process was determined, and the parts to be distributed and automated were identified to propose a distributed and automated line heating system based on modularization and network. Information and data flow from production design to robot control have been analyzed and integrated in the system. The system has two main processes: the calculation of the line heating information and execution of a working unit without calculation. A prototype of the system has been developed to study the feasibility of the system. Tests were carried out by using real production design data of a middle-sized Korean shipyard.

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Automatic Line-Heating Process for Forming the Double-Curved Shell Plates

Journal of Ship Production ◽

10.5957/jsp.2009.25.1.7 ◽

2009 ◽

Vol 25 (01) ◽

pp. 7-13

Author(s):

Ji Wang ◽

Yujun Liu ◽

Zhuoshang Ji ◽

Yanping Deng ◽

Jun Zhang

Keyword(s):

Loop System ◽

Automatic Line ◽

Heating Process ◽

Prediction System ◽

Plate Surface ◽

Technological Parameters ◽

Line Heating ◽

Information Measuring ◽

Automated Line

An automatic line-heating process for the double-curved shell plates is introduced. This process contains four subprocesses: calculating the heating information based on shell development and analysis of primary technological parameters, which is named as prediction system of heating information; heating the plate by an automated line-heating machine according to the calculated heating information; measuring and inspecting the plate surface to determine whether it matches the designed surface; and calculating the reheating information for the deformed plate and reheating the plate automatically until the designed shape is achieved. Therefore, an iterative loop system of an automated line-heating process can be developed based on the integration of these four components.

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Advanced Line-Heating Process for Hull-Steel Assembly

Journal of Ship Production ◽

10.5957/jsp.2000.16.2.121 ◽

2000 ◽

Vol 16 (02) ◽

pp. 121-132

Author(s):

Morinobu Ishiyama ◽

Yoshihiko Tango

Keyword(s):

Steel Plate ◽

Steel Plates ◽

Heating Process ◽

The Finite Element Method ◽

Line Heating ◽

Thermal Forming ◽

Computer Aided ◽

Hull Steel ◽

Advanced Line ◽

Automated Line

Ishikawajima-Harima Heavy Industries Co., Ltd. (IHI) has successfully employed the logic of the Finite Element Method on the principle of Thermal Forming or Line Heating, which facilitates use of computer aided, fully automated line heating machines for forming any curvature precisely and efficiently on a hull steel plate in the shipbuilding process. It is undesirable for the future in line heating that only an experienced technician is able to be skilled in the use of existing line heating f1 or steel plate forming. Accuracy of shape formed by existing line heating is not necessarily well controlled and work at succeeding stages is adversely affected by inaccurate interim products, though it is a very useful method informing steel plates and all apparatus required for line heating is just light tools. The IHI-Advanced Line-heating Process for Hull-steel Assembly (IHI-ALPHA) has succeeded in solving these problems.

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Heating Path Generation and Simulation for Ship Plate Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.421.250 ◽

2011 ◽

Vol 421 ◽

pp. 250-253

Author(s):

Hu Zhu ◽

Xiao Guang Yang

Keyword(s):

Steel Plate ◽

Simulation System ◽

Simulation Software ◽

Heating Process ◽

Path Generation ◽

Plate Steel ◽

Heating Equipment ◽

Line Heating ◽

Steel Base

To lay the foundation of the automation for line heating forming, a method for heating path generation and simulation for ship plate steel base on STL mode was proposed in this paper. The line heating path was generated by slicing the STL model of the steel plate using a series of planes, and the models of the heating equipment of ship plate steel were build, and the heating process of ship plate steel can be simulated by inputting the models of the heating equipment into the simulation system that was built by using VC++ and OpenGL. The case study shows that the method can primely solve the inconvenient of manual heating and the whole heating process can be observed by the simulation so that the heating process can be made a reasonable monitoring, and the heating path generation and simulation software are runs stably and reliably.

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Efficient Algorithms for Inspection and Reforming of Double-Curved Plates in Line-Heating Process

Journal of Ship Production ◽

10.5957/jsp.2006.22.3.184 ◽

2006 ◽

Vol 22 (03) ◽

pp. 184-193

Author(s):

Yujun Liu ◽

Zhuoshang Ji ◽

Yanping Deng ◽

Jun Zhang ◽

Ji Wang

Keyword(s):

Manufacturing Process ◽

Three Dimensional ◽

Efficient Algorithms ◽

Heating Process ◽

Line Heating ◽

Technical Parameters ◽

Error Analyses ◽

Metal Plates ◽

Plate Formation ◽

Prospective Application

Line heating is an effective and economical method for forming metal plates into three-dimensional shaped plates for ships, trains, and airplanes. When a curved plate subject to deformation is formed in line-heating process, the deformed shape is repeatedly inspected and reformed to reach the designed shape. Efficient automatic inspection and reforming processes are essential to enhance productivity in the whole manufacturing process. In this paper, efficient algorithms for inspection and reforming of double-curved plates are introduced. These algorithms have been developed to automatically inspect the transverse and longitudinal shape of plate surfaces and provide technical parameters to reform the unformed plates. The longitudinal shape of the plate surface is examined based on a shell plate development with plastic deformation during the plate formation, and the transverse shape is inspected through error analyses of transverse curvature radiuses. How to use the inspection results to reform unformed plates is discussed. In the end, experiments are performed with comparison to the current industrial plate manufacture, and results show a prospective application of our algorithms to the practical manufacturing of doublecurved plates. The methods presented in this study may play a role in realizing the automation of the entire curved-plate manufacturing process.

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Prediction of Deformations of Steel Plate by GEP in Forming Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.544.268 ◽

2012 ◽

Vol 544 ◽

pp. 268-273

Author(s):

Lei Yang ◽

Liang Gao

Keyword(s):

Mathematical Model ◽

Influencing Factors ◽

Steel Plate ◽

Heating Process ◽

Forming Process ◽

Line Heating ◽

Main Method ◽

Plate Deformation ◽

Final Deformation

Line heating is the main method for forming compound curved shells of hull. The accuracy of final deformation and the productivity depend on the experience of the workers. To predict the plate deformation, the explicit mathematical model for deformation and the main influencing factors by FEA and GEP is established in this paper. The main influencing factors in line heating process were analyzed firstly. Then, 16 group deformation results of steel plate under the five main influencing factors were obtained by FEA. At last, the explicit mathematical model for deformation and the main influencing factors was established.

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Development of Computer-Aided Process Planning System for Plate Bending by Line Heating (Report 3)—Relation Between Heating Condition and Deformation

Journal of Ship Production ◽

10.5957/jsp.1994.10.4.248 ◽

1994 ◽

Vol 10 (04) ◽

pp. 248-257 ◽

Cited By ~ 1

Author(s):

Yukio Ueda ◽

Hidekazu Murakawa ◽

Ahmed Mohamed Rashwan ◽

Isao Neki ◽

Ryoichi Kamichika ◽

...

Keyword(s):

Three Dimensional ◽

Planning System ◽

Heating Process ◽

Plate Bending ◽

Heating Condition ◽

Line Heating ◽

Computer Aided Process Planning ◽

Dimensional Finite Element ◽

General Relations ◽

Three Dimensional Finite Element

An effective plate bending process by line heating can be achieved when the heating conditions are properly selected to produce desirable bending or inplane deformations. To make such decisions on he heating condition, the relation between heating conditions and deformations must be clarified. For his purpose, the authors studied the similarity rule which holds for the line heating process and derived wo parameters governing the deformations. Also, they developed new three-dimensional finite-element method codes as versatile tools to replace costly experiments. The validity of these codes is examined through comparison with an experiment, and they are applied to study the general relations between he parameters and the deformations of plates.

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CHARACTERIZATION AND ANALYSES ON RESIDUAL STRESS AND DEFORMATION DISTRIBUTION IN LINE HEAT PROCESS

The International Journal of Maritime Engineering ◽

10.5750/ijme.v158ia4.1001 ◽

2021 ◽

Vol 158 (A4) ◽

Author(s):

B Zhou ◽

X Han ◽

W Guo ◽

Z Liu ◽

S-K Tan

Keyword(s):

Residual Deformation ◽

Element Model ◽

Heating Process ◽

Stress Distributions ◽

Forming Process ◽

Line Heating ◽

Bending Process ◽

Stress And Deformation ◽

The Impact ◽

Residual Stress And Deformation

Line heating is an important plate bending process that has been adopted in shipyards for more than 60 years. This paper presents the results of a numerical and experimental study on the residual deformation and stress distribution in the plate forming process using the line heating method. In this paper, a finite element model was used to simulate the heating process, and the model was validated using experimental results. The model was then used to analyze the deformation and stress distributions in the heating and non-heating region. The impact of line heating and sequence of heating on both sides of a steel plate was discussed. The findings of the study show that the compression stress generated help to increase the shrinkage of line heating process. This study presents a valuable reference for similar thermal process.

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Study on Forced Convection Boundary Condition for Subcooled Water in the Simulation of Line-Heating Process

Journal of Ship Production ◽

10.5957/jsp.2006.22.1.41 ◽

2006 ◽

Vol 22 (01) ◽

pp. 41-47

Author(s):

Wang Ji ◽

Liu Yujun ◽

Ji Zhuoshang ◽

Deng Yanping ◽

Zhang Jun

Keyword(s):

Boundary Condition ◽

Forced Convection ◽

Great Influence ◽

Nucleate Boiling ◽

Heating Process ◽

Convection Coefficient ◽

Line Heating ◽

Subcooled Water ◽

Convection Boundary Condition ◽

Convection Boundary

In the simulation of line-heating process, the convection boundary condition, especially the subcooled water forced convection, has great influence on the result. The calculation of the convection coefficient is a difficult problem in the simulation. This paper uses the theory of forced convection boiling to study subcooled water forced convection during the line-heating process. By solving the wall temperatures of originating nucleate boiling and critical heat flux for subcooled water and comparing the plate temperature with these two wall temperatures, the status of water can be determined, and then the corresponding convection coefficient is calculated. The simulation results show that the precision of the forced convection boiling boundary condition presented in this paper is much better than that of a boundary condition based on the pool boiling curve.

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