Evaluation of residual stress assessment methods using a repair weld benchmark

2010 ◽  
Vol 45 (3) ◽  
pp. 197-208
Author(s):  
L K Keppas ◽  
R C Wimpory ◽  
D E Katsareas ◽  
N K Anifantis ◽  
A G Youtsos
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Assessment Tools ◽  
Temperature History ◽  
Stress Assessment ◽  
Dimensional Finite Element ◽  
Full Annealing ◽  
Three Dimensional Finite Element

A simple design of a letterbox-type repair weld on a plate is evaluated as a benchmark problem. Residual stresses are recorded using the non-destructive neutron diffraction technique and compared with predictions by full three-dimensional finite element modelling. The comparison is performed over a number of path lines in an attempt to evaluate both methods as potential residual stress assessment tools, for weld repairs. The proposed finite element methodology is based on uncoupled quasi-static thermoelasticity and incorporates the element activation–deactivation technique for simulating weld deposition. Sensitivity analysis indicates that the effect of heat loss due to radiation on predicted residual stresses is negligible, whereas incorporation of full annealing into the model is recommended. The diffractometer used, is STRESS-SPEC, located at the FRMII research reactor (Munich, Germany) and comprises a highly flexible monochromator arrangement and a two-dimensional position-sensitive 3He detector. The success of the repair weld benchmark design is illustrated by not only the satisfactory correlation between experimental and computational results in the form of residual stress but also temperature history data.

Three-Dimensional Finite Element Analysis of the Cold Expansion of Fastener Holes in Two Aluminum Alloys

2002 ◽  
Vol 124 (2) ◽  
pp. 140-145 ◽  
Author(s):  
Jidong Kang ◽  
W. Steven Johnson ◽  
David A. Clark
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Aluminum Alloys ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Element Analysis ◽  
Hardening Models ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

A three-dimensional finite element analysis is developed for the cold expansion process in two aluminum alloys, 2024-T351 and 7050-T7451. The entire cold working process including hole expansion, elastic recovery, and finish reaming is simulated. Both isotropic hardening and kinematic hardening models are considered in the numerical calculations. The results suggest that a three-dimensional nature exists in the residual stress fields surrounding the hole. There are significant differences in residual stresses at different sections through the thickness. However, residual stress at the surface is shown to remain the same for the different plastic hardening models after the hole has recovered and finish reaming has been performed. The reaming of the material around the hole has slight effect on the maximum value and distribution of residual stresses. A comparison has been drawn between the FEA of average through thickness strain and a previous experimental investigation of strain that utilized neutron diffraction and modified Sachs boring on a 7050 aluminum specimen containing a cold expanded hole. The different methods show very good agreement in the magnitude of strain as well as the general trend. The conclusions obtained here are beneficial to the understanding of the phenomenon of fatigue crack initiation and growth at the perimeter of cold worked holes.

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

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.

scholarly journals Three-dimensional finite element simulation of residual stresses in UIC60 rails during the quenching process

2017 ◽  
Vol 21 (3) ◽  
pp. 1301-1307 ◽  
Author(s):  
Nejad Masoudi ◽  
Mahmoud Shariati ◽  
Khalil Farhangdoost
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Residual Stresses ◽  
Initial Conditions ◽  
Three Dimensional ◽  
Analysis Model ◽  
Element Analysis ◽  
Quenching Process ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The aim of this paper is to develop means to predict accurately the residual stresses due to quenching process of an UIC60 rail. A 3-D non-linear stress analysis model has been applied to estimate stress fields of an UIC60 rail in the quenching process. A cooling mechanism with water spray is simulated applying the elastic-plastic finite element analysis for the rail. The 3-D finite element analysis results of the studies presented in this paper are needed to describe the initial conditions for analyses of how the service conditions may act to change the as-manufactured stress field.

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.

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.

Three Dimensional Finite Element Analysis of a Split-Sleeve Cold Expansion Process

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
S. Ismonov ◽  
S. R. Daniewicz ◽  
J. C. Newman ◽  
M. R. Hill ◽  
M. R. Urban
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Residual Stress Field ◽  
Expansion Process ◽  
Element Analysis ◽  
Cold Expansion ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

A cold expansion process is used to prolong the fatigue life of a structure under cyclic loadings. The process produces a beneficial compressive residual stress zone in the hole vicinity, which retards the initiation and propagation of the crack at the hole edge. In this study, a three-dimensional finite element model of the split-sleeve cold expansion process was developed to predict the resulting residual stress field. A thin rectangular aluminum sheet with a centrally located hole was considered. A rigid mandrel and an elastic steel split sleeve were explicitly modeled with the appropriate contact elements at the interfaces between the mandrel, the sleeve, and the hole. Geometrical and material nonlinearities were included. The simulation results were compared with experimental measurements of the residual stress. The influence of friction and the prescribed boundary conditions for the sheet were studied. Differences between the split-sleeve- and the non-split-sleeve model solutions are discussed.

Effect of Initial Thickness to Cut End Deformation of Hat Shape Channel Steel by Roll Forming

2014 ◽  
Vol 622-623 ◽  
pp. 1132-1138 ◽  
Author(s):  
Siti Nadiah binti Mohd Saffe ◽  
Nagamachi Takuo ◽  
Ona Hiroshi
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Three Dimensional ◽  
Roll Forming ◽  
Initial Thickness ◽  
Front End ◽  
Element Simulation ◽  
Metal Thickness ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

A hat channel, also called a furring channel, is a channel with a bottom horizontal web and two vertical flanges, as well as an outward lip that is fabricated by roll forming. When the channel is cut off at a specified length, the edge of the product will change due to the release of residual stress, and this change is generally called cut end deformation. The cut end deformation of channel steel was investigated via experiment and three-dimensional finite-element simulation. The effect of initial thickness on the cut end deformation of hat channel steel was studied. For hat channel steel, the deformations at the front end and back end increase when the sheet metal thickness increases. However, the influence of initial thickness on the cut end deformation of hat-shape channel steel is small.

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