Advanced

Experimental study on the possibility of detecting internal decay in standing Picea abies by blind impact response analysis

Axmon, Joakim LU ; Sandsten, Maria LU and Sörnmo, Leif LU (2004) In Forestry 77(3). p.179-192
Abstract
This paper considers detection of internal decay in standing trees of species Picea abies (L.) Karst. The novel approach is based on two-dimensional spatiotemporal modal analysis of a cross-section which is excited by the hand-made impact of a hammer. An array of accelerometers is distributed around the cross-section, and the resulting impact response is analysed. The temporal frequency for a special spatial mode-shape is used for comparisons on a tree-to-tree basis. The mechanical properties of wood are inherently variable as they are for most materials of biological origin. This leads to a scatter of the analysed parameters that hinders detection of decay based on the temporal frequencies alone. Using regression analysis, we show that by... (More)
This paper considers detection of internal decay in standing trees of species Picea abies (L.) Karst. The novel approach is based on two-dimensional spatiotemporal modal analysis of a cross-section which is excited by the hand-made impact of a hammer. An array of accelerometers is distributed around the cross-section, and the resulting impact response is analysed. The temporal frequency for a special spatial mode-shape is used for comparisons on a tree-to-tree basis. The mechanical properties of wood are inherently variable as they are for most materials of biological origin. This leads to a scatter of the analysed parameters that hinders detection of decay based on the temporal frequencies alone. Using regression analysis, we show that by incorporating the additional information on a surface wave propagation velocity, the scatter of sound trees is significantly reduced. The performance of a detector rule which incorporates the frequency and the surface wave propagation velocity is investigated and found to be better than performance reported for visual tree examination. The analyses are based on the impact responses from 94 standing trees, with 66 sound and 28 in various stages of decay. The proposed technique is yet to be considered an experimental tool. Further research, e.g. on how the mechanical properties are influenced by various environmental factors, is needed before the technique can be applied operationally. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Forestry
volume
77
issue
3
pages
179 - 192
publisher
Oxford University Press
external identifiers
  • wos:000222123100001
  • scopus:3242669074
ISSN
1464-3626
DOI
10.1093/forestry/77.3.179
language
English
LU publication?
yes
id
584207a2-7b79-4c0b-bdc9-52ef44edf4cd (old id 627372)
date added to LUP
2007-11-29 11:42:41
date last changed
2017-10-29 04:12:44
@article{584207a2-7b79-4c0b-bdc9-52ef44edf4cd,
  abstract     = {This paper considers detection of internal decay in standing trees of species Picea abies (L.) Karst. The novel approach is based on two-dimensional spatiotemporal modal analysis of a cross-section which is excited by the hand-made impact of a hammer. An array of accelerometers is distributed around the cross-section, and the resulting impact response is analysed. The temporal frequency for a special spatial mode-shape is used for comparisons on a tree-to-tree basis. The mechanical properties of wood are inherently variable as they are for most materials of biological origin. This leads to a scatter of the analysed parameters that hinders detection of decay based on the temporal frequencies alone. Using regression analysis, we show that by incorporating the additional information on a surface wave propagation velocity, the scatter of sound trees is significantly reduced. The performance of a detector rule which incorporates the frequency and the surface wave propagation velocity is investigated and found to be better than performance reported for visual tree examination. The analyses are based on the impact responses from 94 standing trees, with 66 sound and 28 in various stages of decay. The proposed technique is yet to be considered an experimental tool. Further research, e.g. on how the mechanical properties are influenced by various environmental factors, is needed before the technique can be applied operationally.},
  author       = {Axmon, Joakim and Sandsten, Maria and Sörnmo, Leif},
  issn         = {1464-3626},
  language     = {eng},
  number       = {3},
  pages        = {179--192},
  publisher    = {Oxford University Press},
  series       = {Forestry},
  title        = {Experimental study on the possibility of detecting internal decay in standing Picea abies by blind impact response analysis},
  url          = {http://dx.doi.org/10.1093/forestry/77.3.179},
  volume       = {77},
  year         = {2004},
}