Numerical Simulation of the Effect of Particle and Substrate Preheating on Porosity Level and Residual Stress of As-sprayed Ti6Al4V Components

In an earlier study, a 3-D thermomechanical coupled finite element model was built and experimentally validated to investigate the evolution of the thermal residual stresses and distortions in electron beam additive manufactured Ti-6Al-4V build plates. In this study, an investigation using this robust and accurate model was focused on an efficient preheating method, in which the electron beam quickly scanned across the substrate to preheat the build plate prior to the deposition. Various preheat times, beam powers, scan rates, scanning paths and cooling times (between the end of current preheat scan/deposition layer and the beginning of the next preheat scan/deposition layer) were examined, and the maximum distortion along the centerline of the substrate and the maximum longitudinal residual stress along the normal direction on the middle cross-section of the build plate were quantitatively compared. The results show that increasing preheat times and beam powers could effectively reduce both distortion and residual stress for multiple layers/passes components.

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

ASME 2010 Pressure Vessels and Piping Conference: Volume 1 ◽

10.1115/pvp2010-25321 ◽

2010 ◽

Cited By ~ 2

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.

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Numerical Simulation of Riveting Process

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.34-35.641 ◽

2010 ◽

Vol 34-35 ◽

pp. 641-645

Author(s):

Hong Shuang Zhang

Keyword(s):

Numerical Simulation ◽

Finite Element Method ◽

Residual Stress ◽

Finite Element ◽

Process Parameters ◽

Static Method ◽

Riveting Process ◽

Relationship Of ◽

The Relationship ◽

Element Method

In order to fully understanding the distribution of residual stress after riveting and the relationship between residual stress and riveting process parameters during riveting, Finite Element Method was used to establish a riveting model. Quasi-static method to solve the convergence difficulties was adopted in riveting process. The riveting process was divided into six stages according to the stress versus time curves. The relationship of residual stress with rivet length and rivet hole clearance were established. The results show numerical simulation is effective for riveting process and can make a construction for the practical riveting.

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Residual stress evaluation in selective-laser-melting additively manufactured titanium (Ti-6Al-4V) and inconel 718 using the contour method and numerical simulation

Additive Manufacturing ◽

10.1016/j.addma.2018.06.002 ◽

2018 ◽

Vol 22 ◽

pp. 571-582 ◽

Cited By ~ 20

Author(s):

Bilal Ahmad ◽

Sjoerd O. van der Veen ◽

Michael E. Fitzpatrick ◽

Hua Guo

Keyword(s):

Numerical Simulation ◽

Residual Stress ◽

Selective Laser Melting ◽

Inconel 718 ◽

Contour Method ◽

Laser Melting ◽

Stress Evaluation

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Numerical Simulation of Welding Residual Stress Distribution on T-joint Fillet Structure

International Journal of Ocean System Engineering ◽

10.5574/ijose.2011.2.2.082 ◽

2012 ◽

Vol 2 (2) ◽

pp. 82-91 ◽

Cited By ~ 1

Author(s):

Se-Yun Hwang ◽

Jang-Hyun Lee ◽

Sung-Chan Kim ◽

Kodakkal Kannan Viswanathan

Keyword(s):

Numerical Simulation ◽

Residual Stress ◽

Stress Distribution ◽

Residual Stress Distribution ◽

Welding Residual Stress

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

International Journal of Modern Physics B ◽

10.1142/s0217979221501757 ◽

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.

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