Determination of Repair Weld Residual Stress in a Tube to Tube-Sheet Joint by Neutron Diffraction and the Finite Element Method

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Yun Luo ◽  
Wenchun Jiang ◽  
Dongfeng Chen ◽  
Robert C. Wimpory ◽  
Meijuan Li ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Diffraction Measurement ◽  
Neutron Diffraction Measurement ◽  
Repair Welding ◽  
Welding Direction ◽  
Element Method

Repair welding is a popular method to repair the leakage zone in tube-to-tubesheet joint of shell-tube heat exchangers. But the repaired residual stresses are generated inevitably and have a great effect on stress corrosion cracking (SCC). In this paper, the effects of repair welding on residual stress were studied by finite element method (FEM) and neutron diffraction measurement. The original weld residual stresses calculated by FEM showed good agreement with neutron diffraction measurement results. After repair welding, the transverse residual stresses change very little while the longitudinal residual stresses are increased in the repair zone. In the nonrepair zone, both the transverse and longitudinal stresses are decreased. The repair welding times have little effect on residual stress distribution. With the increase of welding length and heat input, the residual stresses increase. Repair opposite to the original welding direction is recommended because the opposite welding direction minimizes the residual stresses.

A Parametric Investigation of the Through-Thickness Residual Stresses in the Thick Weld Plate Considering Back Chipping: Neutron Diffraction and Finite Element Method

2019 ◽  
Vol 795 ◽  
pp. 276-281
Author(s):  
Yu Wan ◽  
Wen Chun Jiang ◽  
Jian Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Heat Input ◽  
Plate Thickness ◽  
Diffraction Measurement ◽  
Obvious Effect ◽  
Interpass Temperature ◽  
Element Method

Neutron diffraction and finite element method were combined to analyze the through-thickness residual stresses in the thick weld plate considering back chipping. Large residual stresses were generated near the surface. Furthermore, the effect of back chipping width, the heat input of the back weld after back chipping, interpass temperature and plate thickness on the residual stresses were conducted by finite element method. The results showed that larger back chipping width could be helpful to decrease the risk of stress corrosion crack. With the decrease of heat input, the stress variation becomes more obvious. The interpass temperature has an obvious effect on the longitudinal residual stresses but little effect on the transverse residual stresses. Nevertheless, the plate thickness has little influence on the residual stress distribution law. Based on the finite element method results, a formula focused on the 10-40 mm thick plates was fitted to calculate residual stresses with the change of depth through thickness, which was verified by neutron diffraction measurement.

Neutron Diffraction Measurement and Finite Element Method Calculation of Residual Stress of a Heat Treated Steel Pipe

2000 ◽  
Vol 39 (Part 1, No. 12A) ◽  
pp. 6652-6657 ◽  
Author(s):  
Kazuko Inoue ◽  
Hisakazu Kawashima ◽  
Junya Sakaguchi ◽  
Nobuaki Minakawa ◽  
Yoshinori Tsuchiya ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Neutron Diffraction ◽  
Diffraction Measurement ◽  
Neutron Diffraction Measurement ◽  
Method Calculation ◽  
Treated Steel ◽  
Heat Treated ◽  
Heat Treated Steel

Modeling Residual Stresses in Superduplex Stainless Steel Welded Pipes Using the Finite Element Method

2013 ◽  
Vol 758 ◽  
pp. 1-10
Author(s):  
Fabiano Rezende ◽  
Luís Felipe Guimarães de Souza ◽  
Pedro Manuel Calas Lopes Pacheco
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Welding Process ◽  
Welding Parameters ◽  
Superduplex Stainless Steel ◽  
Mechanical Components ◽  
Element Method

Welding is a complex process where localized and intensive heat is imposed to a piece promoting mechanical and metallurgical changes. Phenomenological aspects of welding process involve couplings among different physical processes and its description is unusually complex. Basically, three couplings are essential: thermal, phase transformation and mechanical phenomena. Welding processes can generate residual stress due to the thermal gradient imposed to the workpiece in association to geometric restrictions. The presence of tensile residual stresses can be especially dangerous to mechanical components submitted to fatigue loadings. The present work regards on study the residual stress in welded superduplex stainless steel pipes using experimental and a numerical analysis. A parametric nonlinear elastoplastic model based on finite element method is used for the evaluation of residual stress in superduplex steel welding. The developed model takes into account the coupling between mechanical and thermal fields and the temperature dependency of the thermomechanical properties. Thermocouples are used to measure the temperature evolution during welding stages. Instrumented hole drilling technique is used for the evaluation of the residual stress after welding process. Experimental data is used to calibrate the numerical model. The methodology is applied to evaluate the behavior of two-pass girth welding (TIG for root pass and SMAW for finishing) in 4 inch diameter seamless tubes of superduplex stainless steel UNS32750. The result shows a good agreement between numerical experimental results. The proposed methodology can be used in complex geometries as a powerful tool to study and adjust welding parameters to minimize the residual stresses on welded mechanical components.

FEA of Residual Stresses in Butt Welded Type Low Carbon Steel Using MMAW Technique

2011 ◽  
Vol 110-116 ◽  
pp. 2686-2692
Author(s):  
Gurinder Singh Brar ◽  
Gurdeep Singh
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Carbon Steel ◽  
Residual Stresses ◽  
Low Carbon Steel ◽  
Pressure Vessels ◽  
Transient Temperature ◽  
Low Carbon ◽  
Element Method

Welding is a reliable and efficient joining process in which the coalescence of metals is achieved by fusion. Welding is widely employed in diverse structures such as ships, aircraft, marine structures, bridges, ground vehicles, pipelines and pressure vessels. When two dissimilar plates are joined by welding process, a very complex thermal cycle is applied to the weldment, which further causes inhomogeneous plastic deformation and residual stress in and around fusion zone and heat affected zone (HAZ). Presence of residual stresses may be beneficial or harmful for the structural components depending on the nature and magnitude of residual stresses. In this study, a finite element analysis has been carried out to analyze the thermo-mechanical behaviour and effect of residual stress state in butt-welded in low carbon steel plates. A coupled thermal mechanical three dimension finite element model was developed. Finite element method based software SolidWorks Simulation, was then used to evaluate transient temperature and residual stress during butt welding of two plates. Plate thickness of 8 mm were used which are normally joined by multi-pass operation by Manual Metal Arc Welding (MMAW) process. During each pass, attained peak temperature and variation of residual stresses in plates has also been studied. The results obtained by finite element method agree well with those from X-ray diffraction method as published by Murugan et al. for the prediction of residual stresses.

Comparison of Brazed Residual Stress and Thermal Deformation between X-Type and Pyramidal Lattice Truss Sandwich Structure: Neutron Diffraction Measurement and Simulation Study

2016 ◽  
Vol 35 (6) ◽  
pp. 567-574 ◽  
Author(s):  
Wenchun Jiang ◽  
Zhiquan Wei ◽  
Yun Luo ◽  
Weiya Zhang ◽  
Wanchuck Woo
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Sandwich Structure ◽  
Thermal Deformation ◽  
Diffraction Measurement ◽  
Neutron Diffraction Measurement ◽  
Pyramidal Structure ◽  
Transverse Stresses ◽  
Type Lattice

AbstractThis paper uses finite element method and neutron diffraction measurement to study the residual stress in lattice truss sandwich structure. A comparison of residual stress and thermal deformation between X-type and pyramidal lattice truss sandwich structure has been carried out. The residual stresses are concentrated in the middle joint and then decreases gradually to both the ends. The residual stresses in the X-type lattice truss sandwich structure are smaller than those in pyramidal structure. The maximum longitudinal and transverse stresses of pyramidal structure are 220 and 202 MPa, respectively, but they decrease to 190 and 145 MPa for X-type lattice truss sandwich structure, respectively. The thermal deformation for lattice truss sandwich panel structure is of wave shape. The X-type has a better resistance to thermal deformation than pyramidal lattice truss sandwich structure. The maximum wave deformation of pyramidal structure (0.02 mm) is about twice as that of X-type (0.01 mm) at the same brazing condition.

Prediction of Residual Stresses in Butt Welded Plates Using Inherent Strains

1993 ◽  
Vol 115 (4) ◽  
pp. 417-423 ◽  
Author(s):  
Y. Ueda ◽  
M. G. Yuan
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
The Finite Element Method ◽  
Butt Weld ◽  
Butt Welds ◽  
Plastic Analysis ◽  
Inherent Strain ◽  
Element Method

The source of residual stresses in the vicinity of a weld may be expressed in terms of inherent strains. The characteristics of the inherent strain distributions in butt welds are investigated. It is found that the patterns vary little with changes in the welding conditions and sizes of the welded plates. With some assumptions, simple formulas are derived for the distribution and magnitude of inherent strain in a butt weld. A method of predicting the residual stress in a butt-welded plate using the characteristics of inherent strain distributions is presented. The validity of the method is confirmed by thermal elasto-plastic analysis using the finite element method (FEM).

scholarly journals Modeling and Calculating of Residual Stress and Strain of Butt Welded Joint

2021 ◽  
Vol 31 (5) ◽  
pp. 58-67
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Welded Joint ◽  
The Finite Element Method ◽  
Force Method ◽  
Stress Components ◽  
Residual Stresses And Strains ◽  
Element Method

The non-uniform thermal expansion and contraction resulting from welding processes cause residual stresses and strains. Experimental studies on measuring welding residual stresses and strains of structure are costly and sometimes they are not possible. Previously, analytical methods with idealized models were developed to determine the welding residual stresses and strain. Recently, numerical methods are constructed to analyze the stresses and the strains in welded structures. This paper presents the calculation results of residual stress and welding strain in butt welded joint of S355J2G3 carbon steel of 5 mm thickness made by MAG welding process with a single pass. The calculation is performed by two methods: the imaginary force method and the finite element method. In the finite element method, the SYSWELD software is used to simulate and to determine residual stresses and strain of this welded joint. The results of finite element method are compared with those of imaginary force method to show the rationality and the advantages of finite element method. The study results have shown that in this welded joint, only the longitudinal and transverse stress components are important and the other stress components are negligible.

Calculation of Residual Stresses in Plastic Deformation Processes

1973 ◽  
Vol 95 (1) ◽  
pp. 283-291 ◽  
Author(s):  
C. H. Lee ◽  
H. Iwasaki ◽  
S. Kobayashi
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Internal Pressure ◽  
Solid Cylinder ◽  
The Finite Element Method ◽  
Concentric Cylinders ◽  
Deformation Processes ◽  
Element Method

Three problems, namely, autofrettage process, plastic upsetting of a solid cylinder, and plane-strain and axisymmetric extrusion, are treated for residual stress calculation. A thick-walled cylinder consisting of two loosely fitted concentric cylinders of different materials is subjected to various levels of internal pressure. The residual stresses were calculated with an emphasis on the case where the inner surface of the cylinder yields again upon removal of the internal pressure. Comparison between the calculations and the measurements is given. The residual stresses in plastic upsetting of a solid cylinder were calculated by the finite-element method. An attempt was also made to simulate the real situation in extrusion by the finite-element method. An estimation of the residual stress distribution is then discussed for axisymmetric extrusion problems.

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