scholarly journals Experimental and Numerical Simulation to Study the Reduction of Welding Residual Stress by Ultrasonic Impact Treatment

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 837
Author(s):  
Jianfei Chen ◽  
Jingyu Chu ◽  
Wenchun Jiang ◽  
Bin Yao ◽  
Fan Zhou ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress State ◽  
Tensile Stress ◽  
Residual Stresses ◽  
Thick Plate ◽  
Welding Residual Stress ◽  
Diffraction Measurement ◽  
Ultrasonic Impact Treatment ◽  
Longitudinal Residual Stress ◽  
Large Tensile Stress

In this study, the effects of ultrasonic impact treatment (UIT) on the residual stress in a repair welding joint are investigated by experimental and finite element methods. A three-dimensional numerical analysis approach including a thermomechanical-coupled welding simulation and dynamic elastic-plastic UIT simulation is developed, which has been validated by X-ray diffraction measurement and indentation strain method. The results show that longitudinal residual stresses basically turned into the small tensile stress state from the large tensile stress state, and transverse residual stresses have mainly turned into compressive stresses from large tensile stress after the UIT. In the thickness direction, the average decrease of longitudinal residual stress is 259.9 MPa, which is larger than the 149.1 MPa of transverse residual stress. The calculated residual stress distribution after the UIT of the thin plate is compared with that of the thick plate in the literature, with the results showing the stress accumulation layer inside the thick plate. The simulation results show that the elastic strains are decreased slightly and the equivalent plastic strain is increased markedly after UIT, which explains the mechanism of residual stress relaxation.

Effect of Misalignment and Weld Induced Residual Stresses on the Local Buckling Response of Pipelines

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Aiman Al-Showaiter ◽  
Farid Taheri ◽  
Shawn Kenny
Keyword(s):  
Residual Stress ◽  
Stress State ◽  
Residual Stresses ◽  
Oil And Gas ◽  
Local Buckling ◽  
Welding Residual Stress ◽  
Combined Stress ◽  
Residual Stress State ◽  
Girth Welding ◽  
Welding Processes

The aim of the present study is to develop numerical modeling procedures to simulate and study the effect of girth weld induced residual stresses and geometric imperfections on the behavior of conventional carbon steel oil and gas pipelines. The effect of welding residual stresses was obtained through computational simulations of the multipass girth weld process. The numerical procedures were calibrated using available pubic domain data on stainless steel. The methodology for conducting the welding simulation is presented. A parametric analysis was conducted using the finite element methods to evaluate the effects of welding residual stress due to girth welding processes, joint-to-joint misalignment associated with the girth weld, internal pressure, axial force, and diameter to wall thickness ratio on the local buckling response of pipelines. The pipeline moment-curvature response was examined to determine the influence of these parameters. For the parameters investigated, results from this study have demonstrated the significance of residual stress state due to welding processes and girth weld misalignment on the local buckling response of pipelines subjected to monotonic loading with combined stress state.

Effects of initial stress state on the subsurface stress distribution after ultrasonic impact treatment on thick specimens

2020 ◽  
pp. 030932472097683
Author(s):  
Chuan Liu ◽  
Jiabin Shen ◽  
Changhua Lin ◽  
Jianfei Wang ◽  
Jianxin Wang
Keyword(s):  
Stress State ◽  
Stress Distribution ◽  
Tensile Stress ◽  
Compressive Stress ◽  
Initial Stress ◽  
Correction Method ◽  
Welding Residual Stress ◽  
Initial Stress State ◽  
Ultrasonic Impact Treatment ◽  
Before And After

Thick welded specimens with different initial stress states were prepared and treated with the ultrasonic impact treatment (UIT). The subsurface stresses before and after UIT were measured by the X-ray diffraction (XRD) method combined with layer removal. The measured results were corrected based on the finite element correction method. The effects of initial high tensile stress and low compressive stress on the in-depth after-UIT stress distributions were investigated. The results show that initial stress has no effects on the stresses induced by the UIT within 1 mm depth and within that depth, UIT can induce almost the same longitudinal and transverse stress curves beneath the surface with a peak compressive stress close to the material yield strength at the depth of near 0.6 mm and 0.8 mm. UIT induces almost the same longitudinal and transverse stresses along with the measured depth under initial low compressive stress state. While under the initial high tensile stress state, the initial stress dominates the final stress distribution over 1 mm depth. Initial high tensile stress (welding residual stress) can reduce the depth of the after-UIT compressive stresses to 62.5% to 75% of that under the initial low-compressive stress state.

scholarly journals Investigation of Clamping Effect on the Welding Residual Stress and Deformation of Monel Plates by Using the Ultrasonic Stress Measurement and Finite Element Method

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Yashar Javadi
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Acoustic Waves ◽  
Stress Measurement ◽  
Fe Analysis ◽  
Ultrasonic Waves ◽  
Welding Residual Stress ◽  
Longitudinal Residual Stress ◽  
Ultrasonic Stress Measurement

Welding of nickel-based alloys is increasingly used in the industry to manufacture many important components of the marine industries, chemical processing, etc. In this study, a 3D thermomechanical finite element (FE) analysis is employed to evaluate residual stresses and deformations caused by the tungsten inert gas (TIG) welding of Monel 400 (Nickel-Copper alloy) plates. The FE results related to the residual stresses and deformations have been verified by using the hole-drilling stress measurement and common dimensional measurement tools, respectively. Residual stresses analyzed by the FE simulation are then compared with those obtained from ultrasonic stress measurement. The ultrasonic stress measurement is based on acoustoelasticity law, which presents the relation between the acoustic waves and the stress of material. The ultrasonic stress measurement is carried out by using longitudinal critically refracted (LCR) waves which are longitudinal ultrasonic waves propagated parallel to the surface inside the tested material. Two welded plates are experimentally prepared (with and without using clamp) to investigate the clamping effect on the welding residual stress and deformations. By utilizing the FE analysis along with the LCR method, the distribution of longitudinal residual stress could be achieved. It has been concluded that the applied methodologies are enough accurate to distinguish the clamping effect on the welding residual stresses and deformations of Monel plates.

Finite Element Analyses of Residual Stresses in Typical Welded Joints Used in Nuclear Power Plants and Comparisons With Experiments

2010 ◽  
Author(s):  
Dean Deng ◽  
Kazuo Ogawa ◽  
Nobuyoshi Yanagida ◽  
Koichi Saito
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Residual Stresses ◽  
Welded Joints ◽  
Nuclear Power ◽  
Power Plants ◽  
Butt Joint ◽  
Welding Residual Stress ◽  
Dissimilar Metal ◽  
Water Reactors

Recent discoveries of stress corrosion cracking (SCC) at nickel-based metals in pressurized water reactors (PWRs) and boiling water reactors (BWRs) have raised concerns about safety and integrity of plant components. It has been recognized that welding residual stress is an important factor causing the issue of SCC in a weldment. In this study, both numerical simulation technology and experimental method were employed to investigate the characteristics of welding residual stress distribution in several typical welded joints, which are used in nuclear power plants. These joints include a thick plate butt-welded Alloy 600 joint, a dissimilar metal J-groove set-in joint and a dissimilar metal girth-butt joint. First of all, numerical simulation technology was used to predict welding residual stresses in these three joints, and the influence of heat source model on welding residual stress was examined. Meanwhile, the influence of other thermal processes such as cladding, buttering and heat treatment on the final residual stresses in the dissimilar metal girth-butt joint was also clarified. Secondly, we also measured the residual stresses in three corresponding mock-ups. Finally, the comparisons of the simulation results and the measured data have shed light on how to effectively simulate welding residual stress in these typical joints.

About Residual Stress State of Castings: The Case of HPDC Parts and Possible Advantages through Semi-Solid Processes

2022 ◽  
Vol 327 ◽  
pp. 272-278
Author(s):  
Elisa Fracchia ◽  
Federico Simone Gobber ◽  
Claudio Mus ◽  
Yuji Kobayashi ◽  
Mario Rosso
Keyword(s):  
Residual Stress ◽  
Stress State ◽  
Residual Stresses ◽  
Casting Process ◽  
Ray Method ◽  
Premature Failure ◽  
Thin Walls ◽  
Residual Stress State ◽  
Semi Solid ◽  
Pressure Die Casting

Nowadays, one of the most crucial focus in the aluminium-foundry sector is the production of high-quality castings. Mainly, High-Pressure Die Casting (HPDC) is broadly adopted, since by this process is possible to realize aluminium castings with thin walls and high specific mechanical properties. On the other hand, this casting process may cause tensile states into the castings, namely residual stresses. Residual stresses may strongly affect the life of the product causing premature failure of the casting. Various methods can assess these tensile states, but the non-destructive X-Ray method is the most commonly adopted. Namely, in this work, the residual stress analysis has been performed through Sinto-Pulstec μ-X360s. Detailed measurements have been done on powertrain components realized in aluminium alloy EN AC 46000 through HPDC processes to understand and prevent dangerous residual stress state into the aluminium castings. Furthermore, a comparison with stresses induced by Rheocasting processes is underway. In fact, it is well known that Semi-Solid metal forming combines the advantages of casting and forging, solving safety and environmental problems and possibly even the residual stress state can be positively affected.

Influence of Weld Residual Stresses on Ductile Crack Behavior in AISI Type 316LN Stainless Steel Weld Joint

2018 ◽  
Author(s):  
Sai Deepak Namburu ◽  
Lakshmana Rao Chebolu ◽  
A. Krishnan Subramanian ◽  
Raghu Prakash ◽  
Sasikala Gomathy
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Crack Growth ◽  
Weld Joint ◽  
Volume Fraction ◽  
Growth Behavior ◽  
Welding Residual Stress ◽  
Crack Growth Behavior ◽  
Ductile Crack ◽  
Ductile Crack Growth

Welding residual stress is one of the main concerns in the process of fabrication and operation because of failures in welded steel joints due to its potential effect on structural integrity. This work focuses on the effect of welding residual stress on the ductile crack growth behavior in AISI 316LN welded CT specimens. Two-dimensional plane strain model has been used to simulate the CT specimen. X-ray diffraction technique is used to obtain residual stress value at the SS 316LN weld joint. The GTN model has been employed to estimate the ductile crack growth behavior in the CT-specimen. Results show that residual stresses influence the ductile crack growth behavior. The effect of residual stress has also been investigated for cases with different initial void volume fraction, crack lengths.

NRC/EPRI Residual Stress Validation Program Phase I: Experimental Specimen Modeling and Measurement

2011 ◽  
Author(s):  
J. Broussard ◽  
P. Crooker
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Phase 1 ◽  
Measurement Techniques ◽  
Corrosion Cracking ◽  
Welding Residual Stress ◽  
Hole Drilling ◽  
Pressurized Water

The US Nuclear Regulatory Commission (NRC) and the Electric Power Research Institute (EPRI) are working cooperatively under a memorandum of understanding to validate welding residual stress predictions in pressurized water reactor primary cooling loop components containing dissimilar metal welds. These stresses are of interest as DM welds in pressurized water reactors are susceptible to primary water stress corrosion cracking (PWSCC) and tensile weld residual stresses are one of the primary drivers of this stress corrosion cracking mechanism. The NRC/EPRI weld residual stress (WRS) program currently consists of four phases, with each phase increasing in complexity from lab size specimens to component mock-ups and ex-plant material. This paper describes the Phase 1 program, which comprised an initial period of learning and research for both FEA methods and measurement techniques using simple welded specimens. The Phase 1 specimens include a number of plate and cylinder geometries, each designed to provide a controlled configuration for maximum repeatability of measurements and modeling. A spectrum of surface and through-wall residual stress measurement techniques have been explored using the Phase 1 specimens, including incremental hole drilling, ring-core, and x-ray diffraction for surface stresses and neutron diffraction, deep-hole drilling, and contour method for through-wall stresses. The measured residual stresses are compared to the predicted stress results from a number of researchers employing a variety of modeling techniques. Comparisons between the various measurement techniques and among the modeling results have allowed for greater insight into the impact of various parameters on predicted versus measured residual stress. This paper will also discuss the technical challenges and lessons learned as part of the DM weld materials residual stress measurements.

Numerical simulation of the effect of ultrasonic impact treatment on welding residual stress

2021 ◽  
pp. 2150175
Author(s):  
Tao Mo ◽  
Jingqing Chen ◽  
Pengju Zhang ◽  
Wenqian Bai ◽  
Xiao Mu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Compressive Stress ◽  
Welded Joints ◽  
Welding Process ◽  
Residual Compressive Stress ◽  
Welding Residual Stress ◽  
304 Stainless Steel ◽  
Residual Tensile Stress ◽  
Ultrasonic Impact Treatment

Ultrasonic impact treatment (UIT) is an effective method that has been widely applied in welding structure to improve the fatigue properties of materials. It combines mechanical impact and ultrasonic vibration to produce plastic deformation on the weld joints surface, which introduces beneficial compressive residual stress distribution. To evaluate the effect of UIT technology on alleviating the residual stress of welded joints, a novel numerical analysis method based on the inherent strain theory is proposed to simulate the stress superposition of welding and subsequent UIT process of 304 stainless steel. Meanwhile, the experiment according to the process was carried out to verify the simulation of residual stress values before and after UIT. By the results, optimization of UIT application could effectively reduce the residual stress concentration after welding process. Residual tensile stress of welded joints after UIT is transformed into residual compressive stress. UIT formed a residual compressive stress layer with a thickness of about 0.13 mm on the plate. The numerical simulation results are consistent with the experimental results. The work in this paper could provide theoretical basis and technical support for the reasonable evaluation of the ultrasonic impact on residual stress elimination and mechanical properties improvement of welded joints.

Process - Property Correlation of Friction Stir Welding of Marine Grade Aluminium Alloy 5083 Using Finite Element Analysis

2021 ◽  
Vol 163 (A2) ◽  
Author(s):  
M Sahu ◽  
A Paul ◽  
S Ganguly
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Finite Element ◽  
Friction Stir Welding ◽  
Residual Stresses ◽  
Process Variables ◽  
Friction Stir ◽  
Stress Region ◽  
Longitudinal Residual Stress ◽  
Process Property

In this article, a 3D finite element based thermo-mechanical model for friction stir welding (FSW) of a marine-grade aluminium alloy 5083 is proposed. The model demonstrates the thermal evaluation and the distribution of residual stresses and strains under the variation of process variables. The temperature profile of the weld joint during the FSW process and the mechanical properties of the joints are also experimentally evaluated. The necessary calibration of the model for the correct implementation of the thermal loading, mechanical loading, and boundary conditions was performed using the experimental results. The model simulation and experimental results are analyses in view of the process-property correlation study. The residual stress was evaluated along, and across the weld, centreline referred as longitudinal and transverse residual stresses, respectively. The magnitude of longitudinal residual stress is noted 60-80% higher than that of the transverse direction. The longitudinal residual stress generated a tensile oval shaped stress region around the tool shoulder confined to a maximum distance of about 25mm from the axis of the tool along the weld line. It encompasses the weld-nugget to thermo-mechanically affected zone (TMAZ), while the parent metal region is mostly experiences the compressive residual stresses. However, the transverse residual stress region appears like wing shaped region spread out in both the advancing and retreating side of the weld and occupying approximately double the area as compared to the longitudinal residual stresses. Overall, the study revealed a corelation between the FSW process variables such as welding speed and the tool rotational speed with the residual stress and the mechanical properties of the joint.

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