Assessment of local timber defects during testing and grading as influenced by machine approval procedure

Andreas Rais, Peter Stapel, Jan Willem Van De Kuilen

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

4 Scopus citations

Abstract

Depending on the utilised principle, many grading machines are only able to measure an average property of the board, for example density or longitudinal eigenfrequency. Other grading machines on the market are able to detect local weaknesses such as knots and therefore try to locate the weakest cross section. The basis for the derivation of settings is a comparison between data of the laboratory and data from the grading machine. A regression model is created containing the machine parameters, which provide the best fit between indicating properties and grade determining properties. If the grading machine detects knots, the maximum knot value between the inner load points (bending test) is used for developing a model. This maximum knot value is also used for deriving settings. It is obvious, that it is not always possible to choose the maximum knot value of the entire board. Consequently, the very same board is assigned to a lower indicating property during testing than during grading in practise.

Original languageEnglish
Title of host publication11th World Conference on Timber Engineering 2010, WCTE 2010
Pages300-304
Number of pages5
StatePublished - 2010
Event11th World Conference on Timber Engineering 2010, WCTE 2010 - Trentino, Italy
Duration: 20 Jun 201024 Jun 2010

Publication series

Name11th World Conference on Timber Engineering 2010, WCTE 2010
Volume1

Conference

Conference11th World Conference on Timber Engineering 2010, WCTE 2010
Country/TerritoryItaly
CityTrentino
Period20/06/1024/06/10

Keywords

  • Bending test
  • Knots
  • Length effect
  • Local weakness
  • Machine grading

Fingerprint

Dive into the research topics of 'Assessment of local timber defects during testing and grading as influenced by machine approval procedure'. Together they form a unique fingerprint.

Cite this