Benchmarking of a destructive technique to determine residual stresses in thick-walled axisymmetric components

1997 ◽  
Vol 32 (2) ◽  
pp. 87-96 ◽  
Author(s):  
D J Sharman ◽  
H L Stark ◽  
D W Kelly
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Pressure Vessels ◽  
Stress Distributions ◽  
Initial Residual Stress ◽  
Gauge Data ◽  
Strain Data ◽  
Incremental Strain ◽  
Element Algorithm

A proposed destructive technique to determine residual stresses in thick-walled axisymmetric pressure vessels employs incremental strain gauge data in a finite element algorithm to construct the initial residual stress distribution. The data acquisition component of the proposed technique has similarities with Sachs' bore out method, enabling independently obtained data to be employed by the finite element algorithm. A comparison between the two methods based on the same strain data enables the accuracy of the finite element algorithm to be assessed. Results to date suggest that the new algorithm determines residual stress distributions to an accuracy comparable with Sachs' bore out method. An advantage that the proposed technique has over Sachs' bore out method is that it can be applied to axisymmetric thick-walled pressure vessels of geometries more complex than plain cylinders.

scholarly journals Finite Element Prediction of Residual Stress Distributions in a Multipass Welded Piping Branch Junction

2006 ◽  
Author(s):  
Wei Jiang ◽  
Kadda Yahiaoui
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Welding Process ◽  
Pressure Vessels ◽  
Welding Residual Stress ◽  
Stress Distributions ◽  
Multipass Welding ◽  
Hexahedral Elements ◽  
Element Removal

Piping branch junctions and nozzle attachments to main pressure vessels are common engineering components used in the power, oil and gas, and shipbuilding industries amongst others. These components are usually fabricated by multipass welding. The latter process is known to induce residual stresses at the fabrication stage which can have severe adverse effects on the in-service behavior of such critical components. It is thus desirable if the distributions of residual stresses can be predicted well in advance of welding execution. This paper presents a comprehensive study of three dimensional residual stress distributions in a stainless steel tee branch junction during a multipass welding process. A full 3D thermo-mechanical finite element model has been developed for this purpose. A newly developed meshing technique has been used to model the complex intersection areas of the welded junction with all hexahedral elements. Element removal/reactivate technique has been employed to simulate the deposition of filler material. Material, geometry and boundary nonlinearities associated with welding were all taken into account. The analysis results are presented in the form of stress distributions circumferentially along the weldline on both run and branch pipes as well as at the run and branch cross sections. In general, this computational model is capable of predicting 3D through thickness welding residual stress, which can be valuable for structural integrity assessments of complex welded geometries.

scholarly journals Finite Element Prediction of Residual Stress Distributions in a Multipass Welded Piping Branch Junction

2006 ◽  
Vol 129 (4) ◽  
pp. 601-608 ◽  
Author(s):  
Wei Jiang ◽  
Kadda Yahiaoui
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Pressure Vessels ◽  
Welding Residual Stress ◽  
Stress Distributions ◽  
Multipass Welding ◽  
Hexahedral Elements ◽  
Element Removal

Piping branch junctions and nozzle attachments to main pressure vessels are common engineering components used in the power, oil and gas, and shipbuilding industries amongst others. These components are usually fabricated by multipass welding. The latter process is known to induce residual stresses at the fabrication stage, which can have severe adverse effects on the in-service behavior of such critical components. It is thus desirable if the distributions of residual stresses can be predicted well in advance of welding execution. This paper presents a comprehensive study of three dimensional residual stress distributions in a stainless steel tee branch junction during a multipass welding process. A full three dimensional thermomechanical finite element model has been developed for this purpose. A newly developed meshing technique has been used to model the complex intersection areas of the welded junction with all hexahedral elements. Element removal/reactivate technique has been employed to simulate the deposition of filler material. Material, geometry, and boundary nonlinearities associated with welding were all taken into account. The analysis results are presented in the form of stress distributions circumferentially along the weld line on both run and branch pipes as well as at the run and branch cross sections. In general, this computational model is capable of predicting three dimensional through-thickness welding residual stress, which can be valuable for structural integrity assessments of complex welded geometries.

Stress and Fatigue Life Modeling of Cannon Breech Closures Including Effects of Material Strength and Residual Stress

2000 ◽  
Vol 123 (1) ◽  
pp. 150-154
Author(s):  
John H. Underwood ◽  
Michael J. Glennon
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Fatigue Life ◽  
Yield Strength ◽  
Residual Stresses ◽  
Solid Mechanics ◽  
Element Model ◽  
Pressure Vessels ◽  
Material Strength ◽  
Element Analysis

Laboratory fatigue life results are summarized from several test series of high-strength steel cannon breech closure assemblies pressurized by rapid application of hydraulic oil. The tests were performed to determine safe fatigue lives of high-pressure components at the breech end of the cannon and breech assembly. Careful reanalysis of the fatigue life tests provides data for stress and fatigue life models for breech components, over the following ranges of key parameters: 380–745 MPa cyclic internal pressure; 100–160 mm bore diameter cannon pressure vessels; 1040–1170 MPa yield strength A723 steel; no residual stress, shot peen residual stress, overload residual stress. Modeling of applied and residual stresses at the location of the fatigue failure site is performed by elastic-plastic finite element analysis using ABAQUS and by solid mechanics analysis. Shot peen and overload residual stresses are modeled by superposing typical or calculated residual stress distributions on the applied stresses. Overload residual stresses are obtained directly from the finite element model of the breech, with the breech overload applied to the model in the same way as with actual components. Modeling of the fatigue life of the components is based on the fatigue intensity factor concept of Underwood and Parker, a fracture mechanics description of life that accounts for residual stresses, material yield strength and initial defect size. The fatigue life model describes six test conditions in a stress versus life plot with an R2 correlation of 0.94, and shows significantly lower correlation when known variations in yield strength, stress concentration factor, or residual stress are not included in the model input, thus demonstrating the model sensitivity to these variables.

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.

Interpretation of residual stress distributions in previously loaded cracked beams

1992 ◽  
Vol 27 (2) ◽  
pp. 77-83 ◽  
Author(s):  
D J Smith ◽  
M A M Bourke ◽  
A P Hodgson ◽  
G A Webster ◽  
P J Webster
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Crack Tip ◽  
Stress Distributions ◽  
Element Analysis ◽  
Sampling Volume ◽  
Neutron Diffraction Technique ◽  
Good Agreement

The measurement and prediction of residual stress distributions in a fatigue pre-cracked and a plastically overloaded A533B steel beam are described. The residual stresses were obtained experimentally using the neutron diffraction technique. Finite element analysis was employed to predict the elastic-plastic response and residual stresses introduced after overloading. Comparison of the experimental results have been made with the finite element predictions (for both plane stress and strain conditions) averaged over the same sampling volume used to make the neutron diffraction measurements. It has been found that good agreement is achieved away from the near crack tip region. However, close to the crack tip the measured compressive residual stresses are significantly smaller than predicted. This difference is attributed to the A533B steel exhibiting a Bauschinger effect and yielding at a lower stress after a stress reversal.

Autofrettaged Cylindrical Vessels and Bauschinger Effect: An Analytical Frame for Evaluating Residual Stress Distributions

2001 ◽  
Vol 124 (1) ◽  
pp. 38-46 ◽  
Author(s):  
Paolo Livieri ◽  
Paolo Lazzarin
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Explicit Form ◽  
Analytical Solutions ◽  
Bauschinger Effect ◽  
Superposition Principle ◽  
Pressure Vessels ◽  
Material Behavior ◽  
Stress Distributions ◽  
Hardening Law

The paper reports analytical solutions valid for residual stresses in cylindrical pressure vessels subjected to autofrettage. The material behavior is thought of as obeying a generic monotonic σ−ε curve and exhibiting the Bauschinger effect during the unloading phase. Under linear and power-hardening conditions, the solution is given in an explicit form. The circumstances under which it is possible to apply the superposition principle also in the presence of localized plasticity are clearly identified. When possible, the final stresses can be obtained by using in an appropriate manner the stress expressions related to the loading phase. Finally, the influence on residual stresses, both of the hardening law and of the shape of the unloading σ−ε curve, is discussed.

Residual Stress Distribution in Hard-Facing of Pressure Relief Valve Seat

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Li Ai ◽  
Xinhai Yu ◽  
Wenchun Jiang ◽  
Wanchuck Woo ◽  
Xiaofeng Ze ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Infrared Imaging ◽  
Element Model ◽  
Pressure Relief Valve ◽  
Stress Distributions ◽  
Relief Valve ◽  
Pressure Relief

In this study, for the hard-facing of spring-loaded pressure relief valve seats, the residual stress distributions after the tungsten inert gas welding, (TIG) postwelded heat treatment and subsequent surface turning were investigated. The heat input parameters of welding were calibrated using an infrared imaging and thermocouples. The residual stress distributions were computed using three-dimensional finite element model. The neutron diffraction approach was employed to verify the finite element calculation. It is found that, the surface temperature during hard-facing welding shows a double ellipsoidal shape with the highest value of around 1570 °C. The high residual stress zones are located exactly under the welded joint except a slight deviation in the hoop direction. The magnitudes of tensile residual stresses in the three directions increase with their corresponding locations from the root of the joint into the base metal. The residual stresses in all of the three directions decrease significantly after the heat treatment. After surface turning, the residual stresses are tensile except for those close to the inner surface that are compressive in axial and radial directions.

Numerical Simulation of Residual Stresses Due to Cladding Process

2007 ◽  
Author(s):  
Dieter Siegele ◽  
Marcus Brand
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Finite Element ◽  
Stress Field ◽  
Residual Stresses ◽  
Base Metal ◽  
Base Material ◽  
Pressure Vessels ◽  
Measured Temperature ◽  
Residual Stress Field

The inner surface of reactor pressure vessels is protected against corrosion by an austenitic cladding. Generally, the cladding is welded on the ferritic base metal with two layers to avoid sub-clad cracks and to improve the microstructure of the cladding material. On the other hand, due to the cladding process and the difference of the thermal expansion coefficient of the austenitic cladding and the ferritic base material residual stresses act in the component. This residual stress field is important for assessing crack postulates in the cladding or subclad flaws in the base metal. For the determination of the residual stress field, plates of RPV steel were cladded and heat treated representative to the RPV relevant conditions. During the cladding process the temperature and distortion were measured as basis for the validation of the finite element simulations. The numerical simulation was performed with the finite element code SYSWELD. The heat source of the model was calibrated on the measured temperature profile. In the analysis, the temperature dependent material properties as well as the transformation behavior of the ferritic base metal were taken into account. The calculated residual stresses show tensile stresses in the cladding followed by compressive stresses in the base metal that are in agreement with measurements with X-ray diffraction technique.

Prediction of Residual Stress Distributions in Welded Sections of P92 Pipes with Small Diameter and Thick Wall based on 3D Finite Element Simulation

2015 ◽  
Vol 34 (3) ◽  
Author(s):  
Xiaowei Wang ◽  
Jianming Gong ◽  
Yanping Zhao ◽  
Yanfei Wang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Small Diameter ◽  
Fe Analysis ◽  
Thick Wall ◽  
Fe Model ◽  
Stress Distributions ◽  
Residual Stress Field ◽  
Heat Treated

AbstractThis study used ABAQUS finite element (FE) software to investigate the residual stress distributions of P92 welded pipes in both the as-weld and post weld heat treated (PWHT) condition. Sequential coupling quasi-static thermo-mechanical in conjunction with moving double ellipsoidal heat source and an element add/remove technique to simulate deposition of new weld material, are combined in the 3D FE analysis. To validate the simulation results, the residual stresses in axial direction at the surface of pipe were measured by X-ray diffraction technique and compared with the results of FE analysis. Detailed characteristic distributions of the residual stresses are discussed. Results show that the FE model can predict the residual stress distributions satisfactorily. Highest residual stresses on the outer surface are found in the last weld bead to be deposited. And the highest tensile residual stress for the full welded section take place in heat affected zone (HAZ) near the middle thickness. Larger residual sstress can be found around the welding start point along the pipe circumference. Comparison of heat treated specimen and untreated specimen illustrates that PWHT has a strong effect on the residual stress field.

Numerical Analysis of Residual Stresses in V-Butt Welded Joint of Two Dissimilar Pipes

2013 ◽  
Author(s):  
Gurinder Singh Brar ◽  
Gurdeep Singh
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Carbon Steel ◽  
Residual Stresses ◽  
Filler Metal ◽  
Welded Joint ◽  
Low Carbon Steel ◽  
Stress Distributions ◽  
Low Carbon

In this paper a three-dimensional welding simulation was carried out by commercially available finite element software to predict temperature and the residual stress distributions in V-butt welded joint of two dissimilar pipes. Low carbon steel and stainless steel pipe welding is widely used in a variety of engineering applications such as oil and gas industries, nuclear and thermal power plants and chemical plants. Inelastic deformations during heat treatment are the major cause of residual stress. Heat during welding causes localized expansion as some areas cool and contract more than others. The stress variation in the weldment can be very complex and can vary between compressive and tensile stresses. The mismatching (in the weld in general) occurs due to joint geometry and plate thickness. Welding procedures and degree of restraints also influences the residual stress distributions. To understand the behavior of residual stress, two dissimilar pipes one of stainless steel and another of low carbon steel with outer diameter of 356 mm and internal diameter 240 mm were butt welded. The welding was completed in three passes. The first pass was performed by Manual TIG Welding using ER 309L as a filler metal. The remaining weld passes were welded by Manual Metal Arc Welding (MMAW) and ER 309L-16 was used as a filler metal. During each pass, attained peak temperature and variation of residual stresses and magnitude of axial stress and hoop stress in pipes has been calculated. The results obtained by finite element method agree well with those from Ultrasonic technique (UT) and Hole Drilling Strain-Gauge (HDSG) as published by Akhshik and Moharrami (2009) for the improvement in accuracy of the measurements of residual stresses.

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