Residual Stress Prediction for Non-Axisymmetric Vessel Penetration Welds

2008 ◽  
Author(s):  
Kazuo Ogawa ◽  
Nobuyoshi Yanagida ◽  
Koichi Saito
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Three Dimensional ◽  
Measurement Data ◽  
Fe Model ◽  
Stress Distributions ◽  
Dimensional Finite Element ◽  
Stress Prediction ◽  
Three Dimensional Finite Element ◽  
Good Agreement

Residual stress distribution in an oblique nozzle jointed to a vessel with J-groove welds was analyzed using a three-dimensional finite element method. All welding passes were considered in a 180-degree finite element (FE) model with symmetry. Temperature and stress were modeled for simultaneous bead laying. To determine residual stress distributions at the welds experimentally, a mock-up specimen was manufactured. The analytical results show good agreement with the experimental measurement data, indicating that FE modeling is valid.

A Three-Dimensional Finite Element Evaluation of a Destructive Experimental Method for Determining Through-Thickness Residual Stresses in Girth Welded Pipes

1986 ◽  
Vol 108 (2) ◽  
pp. 99-106 ◽  
Author(s):  
E. F. Rybicki ◽  
J. R. Shadley
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Experimental Method ◽  
Three Dimensional ◽  
Element Model ◽  
Stress Distributions ◽  
Reference Stress ◽  
Improvement Process ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The accuracy of a destructive, experimental method for the evaluation of through-thickness residual stress distributions is investigated. The application of the method is to a welded pipe that has been subjected to a residual stress improvement process. The residual stress improvement process introduces gradients in the stress distribution. The question of interest is how well the back-computation method used to interpret the experimental data represents the residual stress distribution for this type of stress profile. To address this question, a finite element model was used to provide a reference stress solution for comparison with the back-computation results of the experimental method. Three-dimensional finite element stress analyses were also conducted to simulate the cutting steps of the destructive laboratory procedure. The residual stress distributions obtained by the back-computation procedure were then compared with the reference stress solutions provided by the finite element model. The comparisons show agreement and indicate that good results can be expected from the experimental method when it is applied to a pipe that has been subjected to a residual stress improvement process, provided that the axial gradient of stress is not too large.

Effect of Deep Cold Rolling on Residual Stress Distributions Between the Treated and Untreated Regions on Ti–6Al–4V Alloy

2016 ◽  
Vol 138 (11) ◽  
Author(s):  
Andre Lim ◽  
Sylvie Castagne ◽  
Chow Cher Wong
Keyword(s):  
Residual Stress ◽  
Cold Rolling ◽  
Tool Path ◽  
Rolling Direction ◽  
Three Dimensional ◽  
Fe Model ◽  
Stress Distributions ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Step Over

The residual stress distributions caused by the deep cold rolling (DCR) process, with a focus on the distributions at the boundary of the treatment zone, are examined in this study. A three-dimensional finite-element (FE) model, validated with experimental residual stress data, is used to study the effect of the process. The residual stress distribution in the crosswise direction (perpendicular to rolling direction) shows a region of tensile residual stress at the start and end of the track that may be a cause for concern. The reason for this region of tensile stress is likely to be due to the reduced treatment of the start and end zones due to the step over and the tool path taken. Other factors that cause a difference between the steady state and the transient zone of the burnished area are also investigated. It is shown that the net material movement causes larger plastic deformation in the boundary zone between the burnished and unburnished region of DCR.

Three-Dimensional Finite-Element Modelling of Deformation in Weld-Based Rapid Prototyping

2006 ◽  
Vol 220 (6) ◽  
pp. 875-885 ◽  
Author(s):  
M P Mughal ◽  
H Fawad ◽  
R A Mufti
Keyword(s):  
Experimental Data ◽  
Residual Stress ◽  
Finite Element ◽  
Gas Metal Arc Welding ◽  
Three Dimensional ◽  
Single Layer ◽  
Mechanical Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Good Agreement

Residual stress-induced deformations are a major cause of tolerance loss in solid freeform fabrication process employing direct metal deposition. In this article, a three-dimensional finite-element (FE) thermo-mechanical model is presented to predict the residual stress-induced deformations with application to processes where material is added using a distributed moving heat source, e.g. gas metal arc welding (GMAW). A sequentially coupled thermo-mechanical analysis is performed simulating buildup of a single layer on a bolted rectangular substrate. The material used in the present study is mild steel, with temperature-dependent material properties and the material modelled as elastic perfectly plastic. The numerical results are compared with experimental data by manufacturing plate-shaped single-layered specimen, using an indigenously developed semi-automatic deposition system. The fusion zone and temperatures predicted by numerical model show good agreement with experimental data, and the deformations of the substrate in bolted and unbolted conditions are also in good agreement. It has been observed that the heat transfer conditions vary during deposition; therefore, any assumption of thermal symmetry is not valid. Thermal cycling during deposition is the main cause of deformations. The effect of bolting is also very important.

Three-Dimensional Finite Element Analysis of Residual Stress in Arteries

2004 ◽  
Vol 32 (2) ◽  
pp. 257-263 ◽  
Author(s):  
M. L. Raghavan ◽  
S. Trivedi ◽  
A. Nagaraj ◽  
D. D. McPherson ◽  
K. B. Chandran
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

scholarly journals Evaluation of the Effects of the Chincup Appliance on the Craniofacial Structures by the Finite Element Analysis

2017 ◽  
Vol 7 ◽  
pp. 219-223
Author(s):  
Beril Demir Karamanli ◽  
Hülya Kılıçoğlu ◽  
Armagan Fatih Karamanli
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Fe Model ◽  
Analysis Method ◽  
Class Iii ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Clinical Changes

Aims The aim of this study is to evaluate the effects of the chincup appliance used in the treatment of Class III malocclusions, not only on the mandible or temporomandibular joint (TMJ) but also on all the craniofacial structures. Materials and Methods Chincup simulation was performed on a three-dimensional finite element (FE) model. 1000 g (500 g per side) force was applied in the direction of chin-condyle head. Nonlinear FE analysis was used as the numerical analysis method. Results By the application of chincup, stresses were distributed not only on TMJ or mandible but also on the circummaxillary sutures and other craniofacial structures. Conclusions Clinical changes obtained by chincup treatment in Class III malocclusions are not limited by only mandible. It was seen that also further structures were affected.

Three Dimensional Finite Element Analyses of Welding Residual Stresses of a Repaired Weld

2018 ◽  
Author(s):  
Mingya Chen ◽  
Weiwei Yu ◽  
Fei Xue ◽  
Francis Ku ◽  
Zhilin Chen ◽  
...  
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Nuclear Power ◽  
Power Plants ◽  
Three Dimensional ◽  
Fe Model ◽  
Dimensional Finite Element ◽  
Surge Line ◽  
Line Slope ◽  
Three Dimensional Finite Element

The objective of this study is to correct installation non-conformance of a surge line using the excavation and re-weld method which is widely used in nuclear power plants. The surge line with a backslope was not at the required design level after initial installation. In order to solve the problem, a repairing technology is shown as follows: the weld was successively excavated and welded again while the surge line slope was corrected with the help of jacks. Because many of the degradation mechanisms relevant to power plant components can be accelerated by the presence of welding residual stresses (WRS), the WRS caused by the repairing process need to be studied. In this paper, the WRS simulation technique employed in this project is sophisticated. It utilizes a 3-D finite element (FE) model, and simulates the weld sequencing and excavation. Moreover, the WRS simulation performed in this project not only uses the un-axisymmetric model, but also considers the deformation caused by the external jacking loads. The results show that the repairing process is effective, and strain damage induced by the welding repair is also acceptable.

Three-Dimensional Finite Element Analysis of Skin-Pass Rolling and New Models for Process Control

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Sung Jin Yoon ◽  
Tae Jin Shin ◽  
Jae Sang Lee ◽  
Sang Moo Hwang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Coupled Analysis ◽  
Stress Profile ◽  
Fe Model ◽  
Element Analysis ◽  
Skin Pass ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

This paper describes in detail the deformation behavior of the rolls and strip predicted from the three-dimensional finite element analysis of skin-pass rolling. The predictions are made on the basis of the coupled analysis of elastic deformation of the rolls and elastic–plastic deformation of the strip. Predictions from the proposed finite element (FE) model are compared with experimental data from laboratory-scale cold rolling mills. Then, proposed are models for the prediction of the roll force profile and for the prediction of the residual stress profile. The prediction accuracy of the models is examined through comparison with the predictions from the FE model.

scholarly journals A Three-Dimensional Finite-Element Model of a Human Dry Skull for Bone-Conduction Hearing

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Namkeun Kim ◽  
You Chang ◽  
Stefan Stenfelt
Keyword(s):  
Finite Element ◽  
Bone Conduction ◽  
Three Dimensional ◽  
Human Head ◽  
Element Model ◽  
Fe Model ◽  
Lateral Direction ◽  
Dimensional Finite Element ◽  
Simulation Results ◽  
Three Dimensional Finite Element

A three-dimensional finite-element (FE) model of a human dry skull was devised for simulation of human bone-conduction (BC) hearing. Although a dry skull is a simplification of the real complex human skull, such model is valuable for understanding basic BC hearing processes. For validation of the model, the mechanical point impedance of the skull as well as the acceleration of the ipsilateral and contralateral cochlear bone was computed and compared to experimental results. Simulation results showed reasonable consistency between the mechanical point impedance and the experimental measurements when Young’s modulus for skull and polyurethane was set to be 7.3 GPa and 1 MPa with 0.01 and 0.1 loss factors at 1 kHz, respectively. Moreover, the acceleration in the medial-lateral direction showed the best correspondence with the published experimental data, whereas the acceleration in the inferior-superior direction showed the largest discrepancy. However, the results were reasonable considering that different geometries were used for the 3D FE skull and the skull used in the published experimental study. The dry skull model is a first step for understanding BC hearing mechanism in a human head and simulation results can be used to predict vibration pattern of the bone surrounding the middle and inner ear during BC stimulation.

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