Effects of transformation plasticity on welding residual-stress fields in thin-walled pipes and thin plates

1985 ◽  
Vol 1 (10) ◽  
pp. 904-908 ◽  
Author(s):  
B. L. Josefson
Keyword(s):  
Residual Stress ◽  
Welding Residual Stress ◽  
Stress Fields ◽  
Thin Plates ◽  
Transformation Plasticity ◽  
Thin Walled

Analysis of circumferentially welded thin-walled cylinders to study the effects of tack weld orientations and joint root opening on residual stress fields

2009 ◽  
Vol 223 (5) ◽  
pp. 1037-1049 ◽  
Author(s):  
N U Dar ◽  
E M Qureshi ◽  
A M Malik ◽  
M M I Hammouda ◽  
R A Azeem
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Arc Welding ◽  
Operating Conditions ◽  
Stress Fields ◽  
Welded Structures ◽  
Prime Concern ◽  
Thin Walled ◽  
Tack Weld ◽  
Welding Processes

In recent years, the demand for resilient welded structures with excellent in-service load-bearing capacity has been growing rapidly. The operating conditions (thermal and/or structural loads) are becoming more stringent, putting immense pressure on welding engineers to secure excellent quality welded structures. The local, non-uniform heating and subsequent cooling during the welding processes cause complex thermal stress—strain fields to develop, which finally leads to residual stresses, distortions, and their adverse consequences. Residual stresses are of prime concern to industries producing weld-integrated structures around the globe because of their obvious potential to cause dimensional instability in welded structures, and contribute to premature fracture/failure along with significant reduction in fatigue strength and in-service performance of welded structures. Arc welding with single or multiple weld runs is an appropriate and cost-effective joining method to produce high-strength structures in these industries. Multi-field interaction in arc welding makes it a complex manufacturing process. A number of geometric and process parameters contribute significant stress levels in arc-welded structures. In the present analysis, parametric studies have been conducted for the effects of a critical geometric parameter (i.e. tack weld) on the corresponding residual stress fields in circumferentially welded thin-walled cylinders. Tack weld offers considerable resistance to the shrinkage, and the orientation and size of tacks can altogether alter stress patterns within the weldments. Hence, a critical analysis for the effects of tack weld orientation is desirable.

Analysis of circumferentially arc welded thin-walled cylinders to investigate the residual stress fields

2008 ◽  
Vol 46 (12) ◽  
pp. 1391-1401 ◽  
Author(s):  
Afzaal M. Malik ◽  
Ejaz M. Qureshi ◽  
Naeem Ullah Dar ◽  
Iqbal Khan
Keyword(s):  
Residual Stress ◽  
Stress Fields ◽  
Thin Walled

Temperature and Residual Stress Fields in an Austenitic Circumferential Pipe Weld

2002 ◽  
Author(s):  
Ruthard Bonn ◽  
Klaus Metzner ◽  
H. Kockelmann ◽  
E. Roos ◽  
L. Stumpfrock
Keyword(s):  
Residual Stress ◽  
Numerical Calculation ◽  
Stress Field ◽  
Quantitative Determination ◽  
Welding Residual Stress ◽  
Stress Fields ◽  
Residual Stress Field ◽  
Circumferential Welds ◽  
The Impact

The main target of a research programme “experimental and numerical analyses on the residual stress field in the area of circumferential welds in austenitic pipe welds”, sponsored by Technische Vereinigung der Großkraftwerksbetreiber e. V. (VGB) and carried out at MPA Stuttgart, was the validation of the numerical calculation for the quantitative determination of residual stress fields in austenitic circumferential pipe welds. In addition, the influence of operational stresses as well as the impact of the pressure test on the residual stress state had to be examined. By using the TIG orbital welding technique, circumferential welds (Material X 10 CrNiNb 18 9 (1.4550, corresponding to TP 347) were produced (geometric dimensions 255.4 mm I.D. × 8.8 mm wall) with welding boundary conditions and weld parameters (number of weld layers and weld built-up, seam volume, heat input) which are representative for pipings in power plants. Deformation and temperature measurements accompanying the welding, as well as the experimentally determined (X-ray diffraction) welding residual stress distribution, served as the basis for the verification of numeric temperature and residual stress field calculations. The material model on which the calculations were founded was developed by experimental weld simulations in the thermo-mechanical test rig GLEEBLE 2000 for the determination of the material behaviour at different temperatures and elasto-plastic deformation. The numeric calculations were carried out with the Finite Element program ABAQUS. The comparison of the calculation results with the experimental findings confirms the proven validation of the developed numerical calculation models for the quantitative determination of residual stresses in austenitic circumferential pipings. The investigation gives a well-founded insight into the complex thermo-mechanical processes during welding, not known to this extent from literature previously.

Residual Stresses and Stress Intensity Factor Calculations for an Orthotropic Steel Deck

2020 ◽  
Author(s):  
Bin Qiang ◽  
Xin Wang
Keyword(s):  
Residual Stress ◽  
Stress Intensity ◽  
Plate Thickness ◽  
Welding Residual Stress ◽  
Stress Fields ◽  
Surface Cracks ◽  
Middle Section ◽  
Intensity Factors ◽  
Aspect Ratios ◽  
Steel Deck

Abstract The welding residual stress in an orthotopic steel deck is investigated through experimental measurements and finite-element simulations. The simulated residual stress fields are in reasonable agreement with the measured results. The weight function method are used to investigate the stress intensity factors (SIFs) at the surface and deepest points of the semi-elliptical surface cracks, subjected to a combination of external load and through-thickness welding residual stress. Different crack aspect ratios and relative depths are analyzed. The results reveal that the transverse residual stress is always tensile through the plate thickness at the middle section, which makes the SIFs of the surface and deepest points larger than those without considering the residual stress. However, the non-linear reduction for transverse residual stress through the thickness causes the SIFs to decrease for aspect ratios of 0.4, 0.6 and 1.0.

Numerical Analysis of Residual Stresses in Hyperbaric Welding

2012 ◽  
Author(s):  
Xiaobo Ren ◽  
Odd M. Akselsen ◽  
Sigmund K. Ås ◽  
Bård Nyhus
Keyword(s):  
Residual Stress ◽  
Numerical Analysis ◽  
Residual Stresses ◽  
Pressure Range ◽  
Structural Integrity ◽  
Sea Water ◽  
Welding Residual Stress ◽  
Transformation Plasticity ◽  
Micro Structure ◽  
Welding Procedure

Hyperbaric welding residual stress is one of the main concerns for deep water operation. This study presents the numerical investigation of residual stresses in hyperbaric welding by using WeldsimS code. The pressure range investigated in this study is from 3 to 35 bar, which corresponds to 30 to 350 msw (Meters of Sea Water). Experiments results indicate that the welding procedure might be significantly influenced within the pressure range studied. A 2D axisymmetric model has been considered in this study to simulate circumferential welding of a pipe. Phase transformations and transformation plasticity during the welding procedure have been taken into account. The main aim of the study is to predict the hyperbaric welding residual stresses. The temperature evolution and the micro-structure were also studied. Results show that residual stresses induced by hyperbaric welding are significant within the pressure range investigated, which should be assessed for the sake of structural integrity.

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