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Evaluation and visualisation of surface defects on auto-body panels

Andersson, Alf LU (2009) In Journal of Materials Processing Technology 209(2). p.821-837
Abstract
The ability to predict surface defects in outer panels is of vital importance in the automotive industry, especially for brands in the premium car segment. Today, measures to prevent these defects cannot be taken until a test part has been manufactured, which requires a great deal of time and expense. The decision as to whether a certain surface is of acceptable quality or not is based on subjective evaluation. it is quite possible to detect a defect by measurement, but it is not possible to correlate measured defects and the subjective evaluation. If all results could be based on the same criteria, it would be possible to compare a surface by both FE simulations, experiments and subjective evaluation with the same result. In order to find... (More)
The ability to predict surface defects in outer panels is of vital importance in the automotive industry, especially for brands in the premium car segment. Today, measures to prevent these defects cannot be taken until a test part has been manufactured, which requires a great deal of time and expense. The decision as to whether a certain surface is of acceptable quality or not is based on subjective evaluation. it is quite possible to detect a defect by measurement, but it is not possible to correlate measured defects and the subjective evaluation. If all results could be based on the same criteria, it would be possible to compare a surface by both FE simulations, experiments and subjective evaluation with the same result. In order to find a solution concerning the prediction of surface defects, a laboratory tool was manufactured and analysed both experimentally and numerically. The tool represents the area around a fuel filler lid and the aim was to recreate surface defects, so-called "teddy bear ears". Several different sheet materials were analysed in order to evaluate their sensitivity to surface defects, and to investigate the possibility to predict defects in different materials. A major problem with the evaluation of such defects is that the panels are evaluated manually and to a great extent subjectivity is involved in the classification and judgement of the defects. In this study the same computer software was used for the evaluation of both the experimental and the numerical results. in this software the surface defects were indicated by a change in the curvature of the panel. The results showed good agreement between numerical and experimental results. Furthermore, the evaluation software gave a good indication of the appearance of the surface defects compared to an analysis done with the existing tools for surface quality measurements, e.g. D-Sight [D-Sight, 2007. http://www.lmint.com] results. Since the agreement between numerical and experimental results was good, this indicates that these tools can be used for an early verification of surface defects in outer panels. (C) 2008 Published by Elsevier B.V. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Finite element method, Simulation, Surface defects, Sheet-metal forming
in
Journal of Materials Processing Technology
volume
209
issue
2
pages
821 - 837
publisher
Elsevier
external identifiers
  • wos:000262135900027
  • scopus:58149154971
ISSN
0924-0136
DOI
10.1016/j.jmatprotec.2008.02.078
language
English
LU publication?
yes
id
8a938eff-d7b3-430b-ba0b-e5299ca667dc (old id 1313332)
date added to LUP
2009-03-12 09:51:40
date last changed
2017-07-30 03:35:33
@article{8a938eff-d7b3-430b-ba0b-e5299ca667dc,
  abstract     = {The ability to predict surface defects in outer panels is of vital importance in the automotive industry, especially for brands in the premium car segment. Today, measures to prevent these defects cannot be taken until a test part has been manufactured, which requires a great deal of time and expense. The decision as to whether a certain surface is of acceptable quality or not is based on subjective evaluation. it is quite possible to detect a defect by measurement, but it is not possible to correlate measured defects and the subjective evaluation. If all results could be based on the same criteria, it would be possible to compare a surface by both FE simulations, experiments and subjective evaluation with the same result. In order to find a solution concerning the prediction of surface defects, a laboratory tool was manufactured and analysed both experimentally and numerically. The tool represents the area around a fuel filler lid and the aim was to recreate surface defects, so-called "teddy bear ears". Several different sheet materials were analysed in order to evaluate their sensitivity to surface defects, and to investigate the possibility to predict defects in different materials. A major problem with the evaluation of such defects is that the panels are evaluated manually and to a great extent subjectivity is involved in the classification and judgement of the defects. In this study the same computer software was used for the evaluation of both the experimental and the numerical results. in this software the surface defects were indicated by a change in the curvature of the panel. The results showed good agreement between numerical and experimental results. Furthermore, the evaluation software gave a good indication of the appearance of the surface defects compared to an analysis done with the existing tools for surface quality measurements, e.g. D-Sight [D-Sight, 2007. http://www.lmint.com] results. Since the agreement between numerical and experimental results was good, this indicates that these tools can be used for an early verification of surface defects in outer panels. (C) 2008 Published by Elsevier B.V.},
  author       = {Andersson, Alf},
  issn         = {0924-0136},
  keyword      = {Finite element method,Simulation,Surface defects,Sheet-metal forming},
  language     = {eng},
  number       = {2},
  pages        = {821--837},
  publisher    = {Elsevier},
  series       = {Journal of Materials Processing Technology},
  title        = {Evaluation and visualisation of surface defects on auto-body panels},
  url          = {http://dx.doi.org/10.1016/j.jmatprotec.2008.02.078},
  volume       = {209},
  year         = {2009},
}