Non-destructive evaluation of glued laminated timber beams
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Journal Title
Journal ISSN
Volume Title
Insinööritieteiden korkeakoulu |
Master's thesis
Authors
Date
2024-01-22
Department
Major/Subject
Building Technology
Mcode
Degree programme
Master's Programme in Building Technology (CIV)
Language
en
Pages
62
Series
Abstract
This study aims to contribute to the non-destructive investigations of glued laminated timber (GLT) beams that emphasize on the evaluation of strength grade, simplifying assessment procedures and identifying members with properties that are expected to be significantly different to the majority. Inspired by the strength grading methods of timber boards, which are visual strength grading and machine grading, 21 GLT beams are first visual inspected and vibration tests are performed after. Single knot width, annual ring width and the existence of pith are documented whereas the measurements of knots are from image processing in Matlab and the other characteristics are observed manually. In vibration tests, vibrating direction, the effects of support stiffness and loading status are investigated. Leveraging the results from above non-destructive indicators, the aims of the study are achieved by identifying the lay up of GLT beams, excluding impossible grade options and detecting members of properties that are expected to be significantly different to the majority by comparing the cumulative density function of the measurements. Assessment procedures are suggested to be simplified by ignoring finger joint location when visual grading GLT beams and performing vibration test in flexural direction before GLT members are disassembled.Description
Supervisor
Fink, GerhardThesis advisor
Fink, GerhardKeywords
non-destructive strength indicator, visual inspection, image processing, vibration test