scholarly journals Predicting Welding Distortion in a Panel Structure with Longitudinal Stiffeners Using Inherent Deformations Obtained by Inverse Analysis Method

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Liang ◽  
Hidekazu Murakawa
Keyword(s):  
Inverse Analysis ◽  
Welding Process ◽  
Strain Theory ◽  
The Other ◽  
Welding Distortion ◽  
Welding Deformation ◽  
Welded Structures ◽  
Longitudinal Stiffeners ◽  
Manufacturing Accuracy ◽  
Inherent Strain

Welding-induced deformation not only negatively affects dimension accuracy but also degrades the performance of product. If welding deformation can be accurately predicted beforehand, the predictions will be helpful for finding effective methods to improve manufacturing accuracy. Till now, there are two kinds of finite element method (FEM) which can be used to simulate welding deformation. One is the thermal elastic plastic FEM and the other is elastic FEM based on inherent strain theory. The former only can be used to calculate welding deformation for small or medium scale welded structures due to the limitation of computing speed. On the other hand, the latter is an effective method to estimate the total welding distortion for large and complex welded structures even though it neglects the detailed welding process. When the elastic FEM is used to calculate the welding-induced deformation for a large structure, the inherent deformations in each typical joint should be obtained beforehand. In this paper, a new method based on inverse analysis was proposed to obtain the inherent deformations for weld joints. Through introducing the inherent deformations obtained by the proposed method into the elastic FEM based on inherent strain theory, we predicted the welding deformation of a panel structure with two longitudinal stiffeners. In addition, experiments were carried out to verify the simulation results.

scholarly journals Welding Distortion Analysis of Hull Blocks using Equivalent Load Method Based on Inherent Strain

2012 ◽  
Vol 56 (02) ◽  
pp. 63-70
Author(s):  
Yong Tai Kim ◽  
Tae Jun Kim ◽  
Tae Yoon Park ◽  
Chang Doo Jang
Keyword(s):  
Finite Element ◽  
High Efficiency ◽  
Welding Process ◽  
Dimensional Accuracy ◽  
Design Stage ◽  
Welding Distortion ◽  
Welding Deformation ◽  
Element Analysis ◽  
Equivalent Load ◽  
Inherent Strain

Welding deformation reduces the dimensional accuracy of ship hull blocks and decreases productivity due to the correction work. Prediction and minimizing of welding distortion at the design stage will lead to higher quality as well as higher productivity. Therefore, the development of an effective method to predict accurately the weld distortion of hull blocks considering the fabrication sequences is required. In the case of hull block welding work in shipyards, the welding process of curved stiffened plates has large amounts of workload. This paper suggests an efficient method for predicting the welding deformation of stiffened curved plates based on the inherent strain theory combined with the finite element method. The equivalent load was determined by integrating inherent strain components which are calculated in the vicinity of heat affected zone using the highest temperature and the degree of restraint. The welding distortion of curved stiffened panels under equivalent load are calculated by elastic analysis and compared with that by intensive elasto-plastic finite element analysis. It is verified that the proposed method has a high efficiency and accuracy.

scholarly journals Comparative study of welding deformation of a stiffened panel under various welding procedures

2017 ◽  
Vol 233 (1) ◽  
pp. 182-191 ◽  
Author(s):  
Zhen Chen ◽  
Qi Yu ◽  
Yu Luo ◽  
R Ajit Shenoi
Keyword(s):  
Large Scale ◽  
Welding Process ◽  
Production Quality ◽  
Welding Distortion ◽  
Stiffened Panel ◽  
Welding Deformation ◽  
Large Scale Structures ◽  
Improve Production Quality ◽  
Scale Structures ◽  
Welding Procedure

The welding distortions of large-scale structures are extraordinary complicated. If an effective tool of predicting welding distortion is available, then marine design and manufacturing engineers can use this to improve production quality and reduce costs. This article focuses on the comparative studies of welding procedure of a stiffened panel. An efficient thermal elasto-plastic finite element method–based procedure is developed to predict the welding deformation and residual stress of structures. A combined shell/solid model is adopted to enhance modeling and calculation efficiency. The welding process of a stiffened panel is simulated. Three welding procedures of simultaneous, successive and bidirectional welding are studied. The results show that welding distortion can be well controlled by adjusting the welding procedure.

Development of Welding Distortion Analysis Method Using Residual Strain as Boundary Condition

2008 ◽  
Vol 580-582 ◽  
pp. 649-654 ◽  
Author(s):  
Yun Sok Ha ◽  
Si Hoon Cho ◽  
Tae Won Jang
Keyword(s):  
Boundary Condition ◽  
Boundary Conditions ◽  
Residual Strain ◽  
The Other ◽  
Welding Distortion ◽  
Thermal Distortion ◽  
Analysis Method ◽  
Distortion Analysis ◽  
Direct Input ◽  
Inherent Strain

There are two ways of conventional thermal distortion analysis. One is thermal elastoplastic analysis and the other is equivalent forces method based on inherent strain. The former needs exorbitant analysis time, while the latter cannot obtain stress results and requires more time with loads modeling on curved plates. To solve those time-consuming problems, a new kind of thermal distortion analysis method was developed. In this method, inherent strains are devised to be used as direct input factors as boundary conditions. Suggested analysis method was already adopted at welding distortion analysis of large hull block, which was considered as impossible.

Prediction of welding deformations of stiffened panels

2002 ◽  
Vol 216 (2) ◽  
pp. 133-143 ◽  
Author(s):  
C D Jang ◽  
C H Lee ◽  
D E Ko
Keyword(s):  
Strain Theory ◽  
Ship Hull ◽  
Design Stage ◽  
Stiffened Panel ◽  
Welding Deformation ◽  
The Finite Element Method ◽  
Stiffened Panels ◽  
Precise Method ◽  
Degree Of Restraint ◽  
Inherent Strain

Welding deformation reduces the accuracy of ship hull blocks and decreases productivity due to the need for correction work. Preparing an error-minimizing guide at the design stage will lead to higher quality as well as higher productivity. Therefore, developing a precise method to predict the weld deformation is an essential part of it. This paper proposes an efficient method for predicting the weld deformation of complicated structures based on the inherent strain theory combined with the finite element method. The inherent strain is defined as the residual plastic strain after the welding heat cycle and is determined using the highest temperature and degree of restraint. In order to calculate precisely the inherent strain in real structures, it should be noted that the degree of restraint changes according to the different fabrication stages. The simulation of a stiffened panel confirmed the applicability of this method to simple ship hull blocks.

Comparison of Different Residual Stress Models of FSW Butt Joints for Thin Aluminum Alloy Plates

2012 ◽  
Vol 463-464 ◽  
pp. 642-646
Author(s):  
Xi Jing Wang ◽  
Na Li ◽  
Zhong Ke Zhang ◽  
Guo Jing Ruan
Keyword(s):  
Aluminum Alloy ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Welding Process ◽  
Welding Distortion ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Inherent Strain ◽  
Inherent Strain Method ◽  
Strain Method

At present, the main methods used to predict welding residual stresses are the three dimensional thermo-elastic-plastic FEA method and the inherent method.Many learners had simulated the residual stresses of FSW used the thermo -elastic-plastic FEA method which was proved to be time consuming and not very effective. The inherent strain method neglects the whole welding process, and predicts distortion using an elastic finite element analysis by applying the inherent strains on the structure. In this paper,the inherent strains are firstly obtained for an flat butt-joint of aluminum alloy through experiments and three dimensional thermo-elastic-plastic FEA. Computational and experimental results showed that the inherent strain method could predict welding distortion with acceptable accuracy and greatly reduced running time when comparing to the thermo-elastic-plastic FEA method.

scholarly journals Analysis and prediction of welding distortion in complex structures using elastic finite element method

2012 ◽  
Vol 6 (11) ◽  
pp. 35
Author(s):  
Adán Vega Sáenz ◽  
Carlos Plazaola ◽  
Ilka Banfield ◽  
Sherif Rashed ◽  
Hidekazu Murakawa
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain Theory ◽  
Typical Case ◽  
Welding Distortion ◽  
Complex Structures ◽  
Ship Structures ◽  
Elastic Plastic ◽  
Inherent Strain ◽  
Element Method

The Elastic Finite Element Method based on the inherent strain theory is used to predict the welding distortion of ship structures. In addition, a method to predict welding distortion of complex structures by using elastic FEM is presented. To evaluate the effectiveness of the proposed method, a typical case of a ship's structure is examined and the resulting welding distortion is compared to that obtained by using thermal elastic-plastic finite element method.

High Temperature Mechanical Behavior of 16Mnq under Constant Constraint Conditions

2008 ◽  
Vol 575-578 ◽  
pp. 947-952 ◽  
Author(s):  
Yi Gao ◽  
Zeng Pan
Keyword(s):  
High Temperature ◽  
Mechanical Behavior ◽  
Significant Influence ◽  
Steel Bridges ◽  
Welding Distortion ◽  
Welding Deformation ◽  
Temperature Constraint ◽  
Series Of Experiments ◽  
Inherent Strain

Welding is a main processing way in the manufacture of steel bridges. Welding deformation is one of the main influencing factors on the quality of steel bridges, which relates to the effect of material mechanical behavior and welding techniques. The welding distortion is considered to be a result from the inherent strain after welding, which dependent on the highest temperature reached and the constraint at each point. 16Mnq is a common structural steel used in railway steel bridges. Thus, the paper addresses the high-temperature mechanical behavior of 16Mnq through a series of experiments under various peak temperatures and constant constraint conditions. Relationships between temperature, constraint and strain at high temperatures were discussed. The yielding phenomenon based on high temperature occurs under a certain condition of both constraint and temperature, and this phenomenon had significant influence on the inherent strain. The results are significant to understand thermal-mechanical behavior of material and to predict the inherent strain under constant constraint conditions during heat circulates of welding.

Prediction of Welding Deformations of CRH380 Aluminum Alloy Side-Wall with Equivalent Thermal Load Method Based on Inherent Strain

2013 ◽  
Vol 652-654 ◽  
pp. 2303-2310 ◽  
Author(s):  
Ya Na Li ◽  
Su Ming Xie ◽  
Jian Hui Zhang
Keyword(s):  
Aluminum Alloy ◽  
Thermal Load ◽  
High Speed ◽  
Large Scale ◽  
Welding Process ◽  
Side Wall ◽  
Welding Distortion ◽  
High Speed Train ◽  
And Control ◽  
Inherent Strain

The manufacture core of CRH380 high-speed train is aluminum alloy welding technology. However, welding residual distortion which occurs in welding process brings unfavorable effect on the quality of high-speed train. As a result, welding distortion forecasting and control become an important and urgent research topic in railway vehicles. Using equivalent thermal load method based on inherent strain given by the formulae, the welding distortion of aluminum alloy side-wall was predicted by an Elastic FEM which consider actual welding conditions. The simulation results were compared with experimentally measured data to evaluate the validity of the model and to verify effectiveness of this method for large-scale welding structure which had long seams.

scholarly journals Geometry and Distortion Prediction of Multiple Layers for Wire Arc Additive Manufacturing with Artificial Neural Networks

2021 ◽  
Vol 11 (10) ◽  
pp. 4694
Author(s):  
Christian Wacker ◽  
Markus Köhler ◽  
Martin David ◽  
Franziska Aschersleben ◽  
Felix Gabriel ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Welding Process ◽  
High Energy ◽  
Welding Distortion ◽  
Direct Energy Deposition ◽  
Direct Energy ◽  
Industrial Use ◽  
Artificial Neural ◽  
Artificial Neural Network Ann ◽  
Wire Arc Additive Manufacturing

Wire arc additive manufacturing (WAAM) is a direct energy deposition (DED) process with high deposition rates, but deformation and distortion can occur due to the high energy input and resulting strains. Despite great efforts, the prediction of distortion and resulting geometry in additive manufacturing processes using WAAM remains challenging. In this work, an artificial neural network (ANN) is established to predict welding distortion and geometric accuracy for multilayer WAAM structures. For demonstration purposes, the ANN creation process is presented on a smaller scale for multilayer beads on plate welds on a thin substrate sheet. Multiple concepts for the creation of ANNs and the handling of outliers are developed, implemented, and compared. Good results have been achieved by applying an enhanced ANN using deformation and geometry from the previously deposited layer. With further adaptions to this method, a prediction of additive welded structures, geometries, and shapes in defined segments is conceivable, which would enable a multitude of applications for ANNs in the WAAM-Process, especially for applications closer to industrial use cases. It would be feasible to use them as preparatory measures for multi-segmented structures as well as an application during the welding process to continuously adapt parameters for a higher resulting component quality.

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