Evaluation of Temperature Distribution in Thermal Forming Process of Steel Plate by Oxy-gas Source Line Heating

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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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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Enhancement of Exit Flow Uniformity by Modifying the Shape of a Gas Torch to Obtain a Uniform Temperature Distribution on a Steel Plate during Preheating

Applied Sciences ◽

10.3390/app8112197 ◽

2018 ◽

Vol 8 (11) ◽

pp. 2197

Author(s):

Thien Ngo ◽

Junho Go ◽

Tianjun Zhou ◽

Hap Nguyen ◽

Geun Lee

Keyword(s):

Temperature Distribution ◽

Temperature Difference ◽

Steel Plate ◽

Flow Distribution ◽

Uniform Temperature ◽

Flow Uniformity ◽

Modified Model ◽

Uniform Temperature Distribution ◽

Basic Model ◽

New Models

The objective of this study is to improve the exit flow uniformity of a gas torch with multiple exit holes for effective heating of a steel plate. The torch was simulated, and combustion experiments were performed for validation. Based on a basic model, three different revised models were designed and analyzed with the software ANSYS FLUENT 18.2. The flow uniformity (γ) of the velocity distribution at the multiple exit holes was investigated with the pressure drop ranging from 100 to 500 Pa. The basic model had flow uniformity ranging from 0.849 to 0.852, but the three new models had γ1 = 0.901–0.912, γ2 = 0.902–0.911, and γ3 = 0.901–0.914, respectively. The maximum percentage difference of the flow uniformity index between the three new models and the basic model was 7.3%. The basic model with nonuniform flow distribution made a temperature difference of the back side of the steel plate from the center to the edge of around 229 °C, while the modified model with uniform flow distribution had a smaller temperature difference of 90 °C. The simulation results showed good agreement with our experimental results for both the basic model and the modified model. The modified gas torch made a wider and more uniform temperature distribution on a preheated steel plate than the basic one. The results revealed that a trade-off between cost and flow uniformity, as well as the new gas torch, could be applied to a steel-plate preheating process before welding.

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Large Scale Metal Forming – A New Automated Technology using Model Based Engineering for Reduced Cost and Higher Productivity of 2D and 3D Metal Part Forming for Shipbuilding

10.5957/smc-2013-p47 ◽

2013 ◽

Author(s):

Jerald E. Jones ◽

Valerie L. Rhoades ◽

Mark D. Mann

Keyword(s):

Metal Forming ◽

Flexible Manufacturing ◽

Large Scale ◽

Thermal Strain ◽

Department Of Energy ◽

Process Models ◽

Forming Process ◽

Line Heating ◽

Process Adjustment ◽

Automated Technology

A DARPA Program a decade ago concentrated on flexible manufacturing – which included the development of manufacturing processes which were Direct CAD-to-Part, and “smart” robot/process controllers which had embedded process models and could “on-the-fly” make process adjustment and produce perfect or near perfect parts with no human intervention. A team, headed by two of the authors, began the development of the LITS-Form (Laser Induced Thermal Strain – Forming) process. The LITS-Form process has evolved, partly supported by both Navy and Department of Energy Small Business Innovative Research (SBIR)funding; and, the addition of induction heating has made the process much faster and more efficient for thicker metal. The process is similar to thermal forming using Line Heating – which many shipyards use to make complex 3D shapes. However, there are several significant advances in the LITS-Form technology. The Physics of the LITS-Form system is fundamentally different from manual Line Heating allowing it to operate up to 100 times as fast. LITS-Form can produce parts with greater accuracy than Line Heating, and is faster than conventional metal forming operations such as the linear brake press.

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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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An approach to reduce stress and defects: a hybrid process of laser cladding deposition and shot peening

Rapid Prototyping Journal ◽

10.1108/rpj-06-2020-0129 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Cited By ~ 1

Author(s):

Xiaoyu Zhang ◽

Dichen Li ◽

Jiale Geng

Keyword(s):

Tensile Stress ◽

Compressive Stress ◽

Laser Cladding ◽

Shot Peening ◽

Hybrid Process ◽

Layer By Layer ◽

Residual Tensile Stress ◽

Forming Process ◽

Content Type ◽

Thermal Forming

Purpose Laser cladding deposition is limited in industrial application by the micro-defects and residual tensile stress for the thermal forming process, leading to lower fatigue strength compared with that of the forging. The purpose of this paper is to develop an approach to reduce stress and defects. Design/methodology/approach A hybrid process of laser cladding deposition and shot peening is presented to transform surface strengthening technology to the overall strengthening technology through layer-by-layer forming and achieve enhancement. Findings The results show that the surface stress of the sample formed by the hybrid process changed from tensile stress to compressive stress, and the surface compressive stress introduced could reach more than four times the surface tensile stress of the laser cladding sample. At the same time, internal micro-defects such as pores were reduced. The porosity of the sample formed by the hybrid process was reduced by 90.12% than that of the laser cladding sample, and the surface roughness was reduced by 43.16%. Originality/value The authors believe that the hybrid process proposed in this paper can significantly expand the potential application of laser cladding deposition by solving its limitations, promoting its efficiency and applicability in practical cases.

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Simulation-Based Tracking of UOE Pipe Yield Strength Considering Various Thickness-to-Diameter Ratios

Volume 3: Structures, Safety, and Reliability ◽

10.1115/omae2018-77786 ◽

2018 ◽

Cited By ~ 1

Author(s):

Jiwoon Yi ◽

Soo-Chang Kang ◽

Hyun-Moo Koh ◽

Jinkyo F. Choo

Keyword(s):

Yield Strength ◽

Bauschinger Effect ◽

Steel Plate ◽

Tensile Yield Strength ◽

Forming Process ◽

Factors Influencing ◽

Simulation Based ◽

Plastic Forming ◽

Final Yield ◽

Flattening Process

The plastic forming processes involved in the production of UOE pipes alter significantly the yield strength of the original steel plate. Numerous studies indicated that the work hardening and Bauschinger effect are the main factors influencing the alteration of the yield strength. Moreover, apart from the forming process itself, the flattening executed on strips sampled from the formed pipe appears to have also nonnegligible effect on the final yield strength that is used as quality index of the formed pipe. Therefore, this study tracks the yield strength of UOE pipe made of API-X70 steel with various thickness-to-diameter ratios by FE-simulation of the forming and flattening processes so as to identify the factors influencing the yield strength of the UOE pipe. The results show that the flattening process constitutes a critical phase in which steel experiences large loss of its tensile yield strength.

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