Simplified Identification Method for Estimating Residual Stress Distribution due to Butt-Welds by Thermo-Elastic Boundary Element Method : Theoretical Method and Numerical Simulation

Ohtake, Yasuhiro

doi:10.1299/kikaia.75.566

Cited by 4 publications

(7 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The accuracy of the evaluated inherent strain was reduced when the number of measurement points was small or the location of the measurement points was far from the welding line. Moreover, the accuracy of the evaluated values of the inherent strains wasn't confirmed in the previous paper (8) when the shape of the inherent strain distribution was changed by the welding process condition. This paper examines the applicability of the proposed method when the inherent strain distributions in the butt-welded plate are either trapezoidal or triangular.…”

Section: Introductionmentioning

confidence: 80%

“…An inverse analysis using thermo-elastic boundary element method was proposed to estimate the inherent strains in the butt-welded plate in the previous paper (8) . The method can estimate the inherent strains from the measurement data.…”

Section: Boundary Element Inverse Analysis For Evaluating Inherent Stmentioning

confidence: 99%

“…Equations (1) and (4) are given by the following equations when the displacement vector {u} and the traction vector {t} on the boundary surface in the analysis model are divided into each vector of unknown and known (8) .…”

Section: Boundary Element Inverse Analysis For Evaluating Inherent Stmentioning

confidence: 99%

“…Previous papers (8), (9) proposed an inverse analysis using thermo-elastic boundary element method (11) to estimate the inherent strains in the butt-welded plate. The method can estimate the inherent strains from a few measurement data, which are measured at points away from the welding line of the butt-welded plate.…”

Section: Introductionmentioning

confidence: 99%

“…Discrepancy principle is also applied to determine a proper value of the regularization parameter. Numerical simulations are conducted for an analysis model which is the same with that in the previous paper (8) . Numerical examples with and without errors in the measured stresses are made in the simulations considering that errors are included in measured stresses.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Boundary Element Inverse Analysis with Regularization for Estimating Welding Residual Stress Distribution in Butt-Welded Plate

Ohtake

Kubo

2012

JMMP

Self Cite

View full text Add to dashboard Cite

This paper deals with an inverse problem for estimating welding residual stresses in a butt-welded plate from measured data. In previous papers, a method of thermo-elastic boundary element inverse analysis was proposed to estimate the inherent strains in the butt-welded plate. It was found in the papers that the accuracy of the evaluated inherent strain in the butt-welded plate was low when the location of the measurement points was far from the welding line or the number of measurement points was small. This paper examines how the shape of the inherent strain distribution affects the accuracy of the estimated results. Trapezoidal and triangular inherent strain distributions were assumed in each analysis model of the butt-welded plate. Numerical simulations were conducted for those analysis models. In the simulations, measurement errors were included in stresses at measurement points. From all calculation results, it was found that the inherent strains in the butt-welded plate were evaluated in high accuracy from a few measured data by using Tikhonov's regularization regardless of the shape of the inherent strain distribution. The residual stresses in the whole butt-welded plate were calculated from the evaluated inherent strains. Accordingly, it became clear that the proposed boundary element inverse analysis with Tikhonov's regularization was useful in evaluating the residual stresses in the butt-welded plate.

show abstract

Section: Introductionmentioning

confidence: 80%

Section: Boundary Element Inverse Analysis For Evaluating Inherent Stmentioning

confidence: 99%

Section: Boundary Element Inverse Analysis For Evaluating Inherent Stmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Boundary Element Inverse Analysis with Regularization for Estimating Welding Residual Stress Distribution in Butt-Welded Plate

Ohtake

Kubo

2012

JMMP

Self Cite

View full text Add to dashboard Cite

show abstract

Identification of welding residual stress of butt-welded plate using the boundary element inverse analysis with Tikhonov's regularization

Ohtake

Kubo

2010

IOP Conf. Ser.: Mater. Sci. Eng.

View full text Add to dashboard Cite

A study on an application of a body force dipole to residual stress analyses with perturbed data

Asano

2017

Mechanical Engineering Letters

View full text Add to dashboard Cite

While there exist many works on the inverse analysis of the residual stress which use the inherent strain or the body force as a stress source, the authors have proposed a body force dipole (BFD) as the source, since it could simulate fairly well shearing deformation and set no limit to a shape of a BFD distributing area. Some sort of regularization is needed to obtain a reasonable BFD solution, when perturbed stresses are used in the inverse analysis as data measured on a surface of a body. The singular value decomposition (SVD) is used for deriving the BFD solution in the present study. There, artificial noise is taken into account as a regularization parameter to reduce the sensitivity of the computed solution to the perturbation of the stress data. A good artificial noise  is chosen based on the L-curve, the plot of the solution norm versus the norm of the stress residual vector. Numerical results for an analytical model demonstrate that the regularization method used in the present work is very effective for deriving the BFD solution which is not too sensitive to the perturbation of the stress and has a suitably small norm. Also, effects of additional displacement data on the solution is discussed, which are excessively defined as boundary conditions so as to guarantee the uniqueness of the residual stress. Numerical results show that the additional displacements and their perturbations have influence on the regularized solution almost nil. And a theoretical examination reveals that a submatrix for the displacement hardly contributes to the eigenvalues, the squares of the singular values of a sensitivity matrix, so that the displacements have little effect on the solution for the present case.

show abstract

Simplified Identification Method for Estimating Residual Stress Distribution due to Butt-Welds by Thermo-Elastic Boundary Element Method : Theoretical Method and Numerical Simulation

Cited by 4 publications

References 5 publications

Boundary Element Inverse Analysis with Regularization for Estimating Welding Residual Stress Distribution in Butt-Welded Plate

Boundary Element Inverse Analysis with Regularization for Estimating Welding Residual Stress Distribution in Butt-Welded Plate

Identification of welding residual stress of butt-welded plate using the boundary element inverse analysis with Tikhonov's regularization

A study on an application of a body force dipole to residual stress analyses with perturbed data

Contact Info

Product

Resources

About