Out-of-plane welding distortion prediction and mitigation in stiffened welded structures

2015 ◽  
Author(s):  
Ninshu Ma ◽  
Jiangchao Wang ◽  
Yasuhisa Okumoto
Keyword(s):  
Welding Distortion ◽  
Welded Structures ◽  
Out Of Plane

Design Support Tool for Prediction of Welding Distortion in Multiply Stiffened Plate Structures: Experimental and Computational Investigation

2005 ◽  
Vol 21 (04) ◽  
pp. 219-234
Author(s):  
Duncan Camilleri ◽  
Tugrul Comlekci ◽  
Thomas G. F. Gray
Keyword(s):  
Large Scale ◽  
Computational Models ◽  
Plane Deformation ◽  
Computational Prediction ◽  
Welding Distortion ◽  
Plate Structures ◽  
Welded Structures ◽  
Welding Sequence ◽  
Out Of Plane ◽  
Welding Processes

Many industries, such as shipbuilding, concerned with the fabrication of fusionwelded plate structures, face increasing challenges to produce lightweight structures. This design requirement is commonly met by using thin-plate, multiply stiffened, welded structures, but severe difficulties and high rectification costs are frequently incurred, related to the evolution of out-of-plane deformations. The overall scope of this study is to improve the applicability of computational prediction of distortion by providing simple and adaptable methodologies, which can be readily validated through experience of application in the industrial context. These methods are designed to be computationally economic and robust, and they are also generic with respect to material properties, welding processes, and thickness. The aim is to provide design engineers with the tools to explore alternative structural and process parameters and hence to find out if the outcomes will be acceptable, prior to embarking on manufacturing operations typical of large-scale welded structures. The validity of the simulations was investigated via full-scale tests where several filletwelded 100 mm × 6 mmstiffeners were attached to 4 m × 1.5 m × 5 mmthick plates, according to different sequences. The computational models were used to optimize the welding scheme with respect to minimum out-of-plane deformation and welding sequence.

Computational methods and experimental validation of welding distortion models

2007 ◽  
Vol 221 (4) ◽  
pp. 235-249 ◽  
Author(s):  
D Camilleri ◽  
P Mollicone ◽  
T G F Gray
Keyword(s):  
Experimental Study ◽  
Residual Stresses ◽  
Thin Plate ◽  
Computational Methods ◽  
Experimental Validation ◽  
Experimental Tests ◽  
Welding Distortion ◽  
Computationally Efficient ◽  
Welded Structures ◽  
Out Of Plane

Multiply-stiffened, thin plate, welded fabrications are used in a wide variety of transport fields, however the resulting out-of-plane distortion associated with welding exacts a severe design penalty. Depending on the information required, the size of the structure under investigation and the computer power at hand, three computational strategies may be considered to predict welding distortion. If prediction of the localized residual stresses from welding is of major importance, then a full transient, uncoupled thermo-elastoplastic analysis is preferred. This method is not readily applicable to predict welding distortions in industrial-scale welded structures. More computationally efficient models are required and two other models are suggested in the current study. A series of experimental tests of a realistic nature were performed to validate the proposed computational strategies. Computational and experimental study of butt and fillet welding of small and industrial size fabrications is considered.

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.

Novel Techniques and Their Applications for Measuring Out-of-Plane Distortion of Welded Structures

1988 ◽  
Vol 4 (02) ◽  
pp. 73-80
Author(s):  
Koichi Masubuchi ◽  
William H. Luebke ◽  
Hiroshi Itoh
Keyword(s):  
Laser Beam ◽  
Laser Interferometry ◽  
Massachusetts Institute ◽  
Massachusetts Institute Of Technology ◽  
Power Laser ◽  
Ongoing Research ◽  
Welded Structures ◽  
Out Of Plane ◽  
Measurement Devices ◽  
Institute Of Technology

Whether or not a certain-amount of planar distortion is critical, a point of consistency in the ship fabrication process is the need to accurately assess an existing degree of distortion in both local and global domains. At the Massachusetts Institute of Technology, three novel measurement devices have been developed as an adjunct to ongoing research. Distortion can now be evaluated either through laser interferometry, low-power laser beam triangulation, or direct surface contact. In addition to describing the operation and construction of the devices, this paper details their particular applications from a ship production/plate forming perspective.

Tolerances and Measuring Strategies in the Virtual Process Chain for Spot Welded Structures; Substitute Modeling and Automating the Calibration Procedure

2015 ◽  
Vol 794 ◽  
pp. 3-10
Author(s):  
Patrick Ackert ◽  
Christian Schwarz ◽  
Reinhard Mauermann ◽  
Dirk Landgrebe
Keyword(s):  
Spot Welding ◽  
Computing Time ◽  
Numerical Procedure ◽  
Calibration Procedure ◽  
Welding Distortion ◽  
Process Chain ◽  
Welded Structures ◽  
Body Construction ◽  
Calibration Samples ◽  
Virtual Process

This paper presents a method with whose help it is possible, to quickly and precisely predict the influence that thermal spot-shaped joining processes has on the dimensional stability of complex component structures even in early planning phase. The welding distortion is calculated in the context of reduced computing time, based upon an experimentally calibrated mechanical substitute model. This expands existing approaches of substitute models and defines both an experimental and numerical procedure for creating adequate calibration samples. In turn, this makes use of the potential obt ained for standardizing the experimental basis for calculating and modelling the distortion to automatically carry out painstaking calibration processes in simulations and experiments in future based upon mathematical model functions. Finally, the limits to applying the substitute spot welding model are verified with reference to its predictability using a complex joining situation of a car body construction.

Benchmark Investigation of Welding-Induced Buckling and Its Critical Condition During Thin Plate Butt Welding

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Jiangchao Wang ◽  
Bin Yi
Keyword(s):  
Finite Element ◽  
Thin Plate ◽  
Measurement Data ◽  
Characteristic Parameter ◽  
Welding Distortion ◽  
Butt Welding ◽  
Buckling Behavior ◽  
Out Of Plane ◽  
Inherent Deformation ◽  
Good Agreement

Welding-induced buckling is a special type of welding distortion occurring during thin plate butt welding and was investigated using both experimental and computational approaches for this benchmark investigation. In addition, the characteristic parameter and its magnitude for the occurrence of welding-induced buckling were also presented. Fundamental theories of the inherent deformation, finite strains, and eigenvalues of the structure stiffness matrix were considered to investigate welding-induced buckling. A series of experiments on thin plate butt welding with different heat inputs were conducted, and buckling behavior was observed from the deformed shape and the distribution of out-of-plane welding distortion. Transient nonlinear thermal elastic–plastic finite element (TEP FE) and elastic finite element (FE) analyses were conducted to predict welding-induced buckling, and the results were in good agreement with the measurement data. Criteria for the occurrence of welding-induced buckling were proposed and discussed. Inherent deformation was considered as a characteristic parameter of buckling behavior during welding, and its critical magnitude was calculated using a loading incremental method and eigenvalue analysis with good agreement.

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