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

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.

Numerical Simulation for Residual Stress and Deformation of Surface Welding on Membrane Water-Wall

2014 ◽  
Vol 490-491 ◽  
pp. 594-599
Author(s):  
Fan Ling Meng ◽  
Ai Guo Liu
Keyword(s):  
Residual Stress ◽  
Great Influence ◽  
Residual Deformation ◽  
Welding Residual Stress ◽  
Finite Element Software ◽  
Welding Sequence ◽  
Surface Welding ◽  
Stress And Deformation ◽  
Welding Sequences ◽  
Residual Stress And Deformation

Automatic MIG was adopted to weld Inconel 625 alloy on 20 G Membrane Waterwall, which can improve the capacities of high temperature corrosion resistance and wear resistance. To study the influence of Membrane Waterwall surface welding sequences on residual stress and residual deformation, this paper utilized finite element software ABAQUS and segmented moving heat source model to simulate the sequence welding, balanced welding from the middle to sides, balanced welding from sides to the middle, balanced skip welding from middle to sides and balanced skip welding from sides to the middle and studied their residual stresses and deformations. The simulation results indicated that there was a great influence of welding sequences on the residual stress and deformation. The optimal welding sequence was balanced skip welding from middle to sides and balanced skip welding from sides to the middle, which could change the stress distribution, decrease the welding residual stress by 17%, realize the even deformation of the whole welding section and decrease the bending deformation by 50%.

Prediction of Deformations of Steel Plate by GEP in Forming Process

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.

Nondimensionalized Relationship Between Heating Conditions and Residual Deformations in the Line Heating Process

2002 ◽  
Vol 46 (04) ◽  
pp. 229-238
Author(s):  
Jong Gye Shin ◽  
Jang Hyun Lee
Keyword(s):  
Residual Deformation ◽  
Relevant Information ◽  
Heating Process ◽  
Line Heating ◽  
Element Analysis ◽  
Regression Methods ◽  
Rigorous Approach ◽  
Variate Analysis ◽  
Input Parameters ◽  
Residual Deformations

The nature of a line heating process is very complex since a variety of factors affects the amount of residual deformation. A linear relationship between input and output parameters, which has been derived from simple experiments, is successively used. This relationship, however, is very limited since it does not include important parameters and the line heating process is not linear. A rigorous approach is presented here in an attempt to obtain new relationships between input parameters and final deformations during the line heating process. The residual deformations are investigated by using a thermal elastic-plastic analysis based on finite-element analysis (FEA). Experiments are carried out in order to verify the validity of the FEA results. The nondimensional input parameters are then determined by the dimensional analysis. The relationships between the input parameters and the residual deformations are developed by using multi-variate analysis (MVA) and multiple-regression methods. The final form of the relationships is nonlinear and includes relevant information.

Effects of Preheat and Interpass Temperature on the Residual Stress and Distortion on the T-Joint Weld

2014 ◽  
Author(s):  
Guangming Fu ◽  
Marcelo Igor Lourenço ◽  
Menglan Duan ◽  
Segen F. Estefen
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Element Model ◽  
Source Model ◽  
Fe Model ◽  
Heat Source Model ◽  
Stress And Deformation ◽  
The Finite Element Model ◽  
Residual Stress And Deformation ◽  
Interpass Temperature

The finite element model of ABAQUS combined with FORTRAN subroutines was developed to predict the residual stress and deformation of T-joint welds under different preheat and inter-pass temperature. A calibrated and sequentially coupled thermal and mechanical 3D finite element (FE) model is developed, and Goldak’s double ellipsoidal heat source model is implemented into the numerical model. The welding induced imperfections, including the residual stress and distortion are discussed in this paper. The results show that vertical deformation depend significantly on the preheat temperature and inter-pass temperature. The influences of preheat and interpass temperature on the residual stress are not significant.

scholarly journals Analisa Pembengkokan Pelat dengan Metode Line Heating

2020 ◽  
Vol 3 (2) ◽  
pp. 91-102
Author(s):  
Pardi Pardi ◽  
Romadhoni Romadhoni ◽  
Budhi Santoso
Keyword(s):  
Heat Input ◽  
Structural Changes ◽  
Heating Temperature ◽  
Heating Process ◽  
Plate Bending ◽  
Three Dimension ◽  
Line Heating ◽  
Heating Method ◽  
Bending Process ◽  
On Line

One method of bending the plates in hull construction can be done either by conventional or by line heating method. The method of line heating has several advantages, such as lesser initial investment and can be used for three dimension form.  This research is focused to obtain the relation between the parameter in line heating process and the conceited of plate curve that produced. With the aim of the curvature of structural changes caused by the heat given during the plate bending process it can be seen for the shipbuilding fabrication process. From the results of this study obtained data on line heating conditions on plates with a thickness of 10 mm (plates A and B) obtained the maximum curvature height is 11.1 mm at a heating speed of 8 mm / s and a heating temperature of 3850 C. Furthermore, the amount of heat input that is applied to material 3327.47 Joules / sec and due to efficiency at 1697,001 Joules / sec. Keyword: Line Heating Method, Line Heating Parameter, Curve Heights

Development of Computer-Aided Process Planning System for Plate Bending by Line Heating (Report 2)—Practice for Plate Bending in Shipyard Viewed from Aspect of Inherent Strain

1994 ◽  
Vol 10 (04) ◽  
pp. 239-247
Author(s):  
Yukio Ueda ◽  
Hidekazu Murakawa ◽  
Ahmed Mohamed Rashwan ◽  
Yasuhisa Okumoto ◽  
Ryoichi Kamichika
Keyword(s):  
Present Report ◽  
Planning System ◽  
Heating Process ◽  
Plate Bending ◽  
Skilled Workers ◽  
Line Heating ◽  
Computer Aided Process Planning ◽  
Bending Process ◽  
Theoretical Predictions ◽  
Inherent Strain

In the plate bending process by line heating, the decisions as to which part of the plate should be heated and in which direction are usually made by skillful workers. However, the number of skilled workers is declining rapidly and in recent years this has become a serious problem in shipyards. To solve the problem, the authors in an earlier report proposed a method to make the decisions based on theoretical analyses focused on inherent strain. The potential usefulness of the method was demonstrated through example problems dealing with mathematical ideal geometry. In the present report, a comparison is made between theoretical predictions and actual shipyard practice in forming curved members of a ship hull, and an attempt is made to visualize the knowledge of skilled workers, which heretofore was invisible, using computer graphic images showing inherent strain. Further, it is demonstrated that the same idea can be applied not only to make decisions on the line heating process but also to design the total plate bending process, including decisions on using the bending roller and the press machine.

Numerical analysis and experimental research of triangle induction heating of the rolled plate

2016 ◽  
Vol 231 (5) ◽  
pp. 844-859 ◽  
Author(s):  
Xuebiao Zhang ◽  
Cheng Chen ◽  
Yujun Liu
Keyword(s):  
Numerical Model ◽  
Induction Heating ◽  
Electromagnetic Coupling ◽  
Element Model ◽  
Rolled Plate ◽  
Heating Process ◽  
Forming Process ◽  
Plate Edge ◽  
Modified Model ◽  
Heating Technology

In shipyard, triangle heating technology with irregular multi-heating paths and highly concentrated heat input is used to form a curved plate, especially a concave type plate. Compared with line heating process with simple line segment path, its main purpose is to get a bigger contraction deformation at the plate edge. Hence, triangle heating technology is important for most shipyards to increase hull-forming productivity and study the automation. This paper focuses on the moveable triangle induction heating technology. An electromagnetic coupling finite element model is built to simulate the moveable triangle induction heating process and reveal the temperature characteristics and deformation behavior. The results of the simulation are compared with those obtained from experiments and show good agreement. It demonstrates that the numerical model used in this study is effective for simulating triangle heating for the steel plate forming process in shipbuilding. With the numerical model, the paper further investigates the effect of heating parameters on temperature and shrinkage deformation. These are traced here with a modified mechanical model whose results are in accord with the numerical results. This modified model can be applied to predict the edge shrinkage and explain the effect of heating parameters on transverse shrinkage.

Analysis of Process Parameters Influencing V-Bending Based on Dynaform

2013 ◽  
Vol 423-426 ◽  
pp. 1858-1861 ◽  
Author(s):  
Guo Ying Ma ◽  
Bin Bing Huang ◽  
Shou Bo Jiang ◽  
Kui Chen
Keyword(s):  
Simulation Analysis ◽  
Mold Design ◽  
Forming Process ◽  
Forming Mechanism ◽  
Stamping Process ◽  
Element Simulation ◽  
Sheet Bending ◽  
Bending Process ◽  
The Impact

On the basis of studying the sheet bending forming mechanism, the process of V-bending has carried on the finite element simulation analysis. Aimed at the phenomenon such as the springback in the sheet forming process, according to the quality of formed parts evaluation index, the impact of changes on stamping parameters such as blank holder force, stamping velocity, friction coefficient was analyzed on the bending process and springback of stamping parts. The parts quality problems encountered in the process of stamping process were predicted, in order to provide a theoretical basis for the stamping process design and mold design to effectively shorten the mold design and production commissioning period.

Ultimate Strength of Damaged Stiffened Panels Subjected to Uniaxial Compressive Loads Accounting for Impact Induced Residual Stress and Deformation

2015 ◽  
Author(s):  
Jie Cai ◽  
Xiaoli Jiang ◽  
Gabriel Lodewijks
Keyword(s):  
Residual Stress ◽  
Ultimate Strength ◽  
Carrying Capacity ◽  
Stiffened Panel ◽  
Load Carrying Capacity ◽  
Stiffened Panels ◽  
Load Carrying ◽  
Stress And Deformation ◽  
The Impact ◽  
Residual Stress And Deformation

In case of ship accidents, the ship’s hull will inevitably suffer from damages such as holes, cracks, dent etc., which will threaten the structural safety of ship. It is essential to study the ultimate strength of damaged ships in order to facilitate the decision-making process of ship salvage. There are considerable publications on the subject, however, the impact of the induced residual stress and deformation are normally excluded in those studies. This paper therefore aims at investigating the effect of the impact induced residual stress and deformation on the ultimate strength of a stiffened panel through application of a nonlinear Finite Element Analysis (FEA) method. Firstly, a literature review on ultimate strength of damaged ships is presented. Secondly, a nonlinear numerical simulation is adopted to investigate the ultimate strength of stiffened panels accounting for residual stress and deformation. this procedure consists of two stages: the impact stage and the static stage. The results of the numerical simulation of both stages are validated through the results of experiments and simulations available in literature. Afterwards, a series of case studies are performed deploying the validated numerical method. Finally, a closed form expression to predict the ultimate strength accounting for impact induced residual stress and deformation is proposed based on direct simulation. Results show that the combined effect of impact induced residual stress and deformation can significantly reduce structures’ load carrying capacity. The maximum reduction ratio reaches 37% in local stiffened panel. The method of removal of all the plastic deformation area is generally too conservative to predict the ultimate strength of a damaged local stiffened panel, which will underestimate the residual load carrying capacity of ships considerably.

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