Full-Field Strain Determination for Additively Manufactured Parts Using Radial Basis Functions

Additively manufactured components, especially those produced in deposition welding processes, have a rough curvilinear surface. Strain and surface deformation analysis of such components is increasingly performed using digital image correlation (DIC) methods, which raises questions regarding interp...

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Main Authors: Stefan Hartmann, Lutz Müller-Lohse, Jendrik-Alexander Tröger
Format: Article
Language:English
Published: MDPI AG 2021-12-01
Series:Applied Sciences
Subjects:
Online Access:https://www.mdpi.com/2076-3417/11/23/11434
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author Stefan Hartmann
Lutz Müller-Lohse
Jendrik-Alexander Tröger
author_facet Stefan Hartmann
Lutz Müller-Lohse
Jendrik-Alexander Tröger
author_sort Stefan Hartmann
collection DOAJ
description Additively manufactured components, especially those produced in deposition welding processes, have a rough curvilinear surface. Strain and surface deformation analysis of such components is increasingly performed using digital image correlation (DIC) methods, which raises questions regarding interpretability of the results. Furthermore, in triangulation or local tangential plane based DIC strain analysis, the principal strain directions are difficult to be calculated at any point, which is due to the non-continuity of the approach. Thus, both questions will be addressed in this article. Apart from classical local strain analysis based on triangulation or local linearization concepts, the application of globally formulated radial basis functions (RBF) is investigated for the first time, with the advantage that it is possible to evaluate all interesting quantities at arbitrary points. This is performed for both interpolation and regression. Both approaches are studied at three-dimensional, curvilinear verification examples and real additively manufactured cylindrical specimens. It is found out that, if real applications are investigated, the RBF-approach based on interpolation and regression has to be considered carefully due to so-called boundary effects. This can be circumvented by only considering the region that has a certain distance to the edges of the evaluation domain. Independent of the evaluation scheme, the error of the maximum principal strains increases with increasing surface roughness, which has to be kept in mind for such applications when interpreting or evaluating the results of manufactured parts. However, the entire scheme offers interesting properties for the treatment of DIC-data.
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spelling doaj.art-38f54a41db4d4dfeaa1078fc498511862023-11-23T02:08:07ZengMDPI AGApplied Sciences2076-34172021-12-0111231143410.3390/app112311434Full-Field Strain Determination for Additively Manufactured Parts Using Radial Basis FunctionsStefan Hartmann0Lutz Müller-Lohse1Jendrik-Alexander Tröger2Institute of Applied Mechanics, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, GermanyInstitute of Applied Mechanics, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, GermanyInstitute of Applied Mechanics, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, GermanyAdditively manufactured components, especially those produced in deposition welding processes, have a rough curvilinear surface. Strain and surface deformation analysis of such components is increasingly performed using digital image correlation (DIC) methods, which raises questions regarding interpretability of the results. Furthermore, in triangulation or local tangential plane based DIC strain analysis, the principal strain directions are difficult to be calculated at any point, which is due to the non-continuity of the approach. Thus, both questions will be addressed in this article. Apart from classical local strain analysis based on triangulation or local linearization concepts, the application of globally formulated radial basis functions (RBF) is investigated for the first time, with the advantage that it is possible to evaluate all interesting quantities at arbitrary points. This is performed for both interpolation and regression. Both approaches are studied at three-dimensional, curvilinear verification examples and real additively manufactured cylindrical specimens. It is found out that, if real applications are investigated, the RBF-approach based on interpolation and regression has to be considered carefully due to so-called boundary effects. This can be circumvented by only considering the region that has a certain distance to the edges of the evaluation domain. Independent of the evaluation scheme, the error of the maximum principal strains increases with increasing surface roughness, which has to be kept in mind for such applications when interpreting or evaluating the results of manufactured parts. However, the entire scheme offers interesting properties for the treatment of DIC-data.https://www.mdpi.com/2076-3417/11/23/11434digital image correlationstrain analysisradial basis functionadditive manufacturingWAAMtension
spellingShingle Stefan Hartmann
Lutz Müller-Lohse
Jendrik-Alexander Tröger
Full-Field Strain Determination for Additively Manufactured Parts Using Radial Basis Functions
Applied Sciences
digital image correlation
strain analysis
radial basis function
additive manufacturing
WAAM
tension
title Full-Field Strain Determination for Additively Manufactured Parts Using Radial Basis Functions
title_full Full-Field Strain Determination for Additively Manufactured Parts Using Radial Basis Functions
title_fullStr Full-Field Strain Determination for Additively Manufactured Parts Using Radial Basis Functions
title_full_unstemmed Full-Field Strain Determination for Additively Manufactured Parts Using Radial Basis Functions
title_short Full-Field Strain Determination for Additively Manufactured Parts Using Radial Basis Functions
title_sort full field strain determination for additively manufactured parts using radial basis functions
topic digital image correlation
strain analysis
radial basis function
additive manufacturing
WAAM
tension
url https://www.mdpi.com/2076-3417/11/23/11434
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