Predicting welding deformation in thin plate panel structure by means of inherent strain and interface element

2012 ◽  
Vol 17 (1) ◽  
pp. 13-21 ◽  
Author(s):  
D Deng ◽  
H Murakawa ◽  
N Ma
2020 ◽  
Vol 8 (6) ◽  
pp. 454
Author(s):  
Donghan Woo ◽  
Mitsuru Kitamura

The accurate numerical prediction of welding deformation is important to improve the structural safety of ships and offshore structures in heavy industries. The precise reflection of the real working condition in the numerical prediction is an essential factor to improve its result. In the present study, the effect of the gravity force on numerical prediction of the optimal welding sequence of a general ship grillage structure was validated with the introduction of a new boundary condition in which the structure is placed over rails. Additionally, the direction of the gravity force of welded structures could be changed at the final assembly process according to the production plan. The effect of the gravitational orientation on the final welding displacements was also investigated herein. The elastic finite element method using the inherent strain, interface element, and multipoint constraint function was introduced to analyze the welding deformation. This study validated the influence of the gravity force on the numerical prediction of welding displacements in a general ship grillage structure.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Liang ◽  
Hidekazu Murakawa

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.


2012 ◽  
Vol 379 ◽  
pp. 012055
Author(s):  
Masashi Hata ◽  
Shinsuke Itoh ◽  
Taketoshi Sugihiro ◽  
Yasuo Yamashita ◽  
Atsushi Kamio ◽  
...  

2013 ◽  
Vol 650 ◽  
pp. 572-576 ◽  
Author(s):  
Pan Zeng ◽  
Le Mei ◽  
Li Ping Lei

Thermal-Elastic-Plastic finite element analysis is introduced to study the deformation of laser welding of thin plate with consideration of varying material parameters. From aspects of numerical simulation and experiment, three welding cases are investigated: (1) the butt welding with constraint clamp, (2) the free bead welding, (3) the bead welding with constraint clamp. At last, the deformation configurations of welding plate under different constraint cases are characterized, and the behaviors of welding deformation are summarized.


2008 ◽  
Vol 24 (4) ◽  
pp. 301-309 ◽  
Author(s):  
Y.-X. Wang ◽  
P. Zhang ◽  
Z.-G. Hou ◽  
C.-Z. Li

AbstractThe transient thermal process of a thin-wall beam with CO2 Gas Metal Arc Welding (GMAW) is analyzed by Finite Element Analysis Method (FEA). The thermal input is simplified as transient section body heat sources and loaded as its actual sequence in the analysis. The transient temperature field obtained can represent the basic characteristics of the real welding process and can be used as the foundation of thermal elastic-plastic analysis. Based on the temperature field, thermal elastic-plastic FEA is performed on the thin-wall beam. The distribution and change of the welding deformation, stress and strain are obtained and compared with the experiment results. Also an improvement can be presented on the inherent strain method. Using the inherent strain method, the welding deformation of the thin-wall beam is calculated. The temperature loading method is developed to load the variable inherent strain value expediently. The loading of inherent strain value on spatial welding line that is unparallel to the global coordinate axis is achieved with the application of element coordinate system. Comparison with the experiment results shows that both the thermal-elastic-plastic analysis and inherent strain analysis method can be used to predict the welding deformation effectively, the results calculated by both the thermal-elastic-plastic analysis and inherent strain analysis are close to the test measure results.


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