Investigation of the effect of tool wear and wood species on surface quality and performance of finger-joint
department or school: Forestry, Faculty of
data provider: DSpace
degree campus: UBCV
creator: Li, Shiqing
issued: 2025-05-29T17:16:18Z
issued: 2025
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Finger-jointed (FJ) lamellas are widely used in mass timber where bonding performance is critical for structural reliability. However, tool wear during FJ can affect wood surface characteristics, potentially affecting adhesive behavior and joint strength. In this study, Coastal Douglas-fir (DF), Hem-Fir (HF), and Western Redcedar (WRC) were machined using freshly sharpened and worn cutting tools and bonded with a polyurethane (PUR) adhesive to evaluate changes in surface topography, surface energy, adhesive wetting, ultimate tensile strength (UTS), and initial friction properties. The findings indicate that worn tool increased surface roughness (SA, SP, SV) for all wood species, which improved initial friction strength (IF-UTS) and coefficient of friction (IF-CoF), enhancing pre-cured joint integrity and stability. For DF, tool wear also increased UTS due to improved mechanical interlocking and adhesive penetration. In contrast, HF and WRC showed decreased UTS under worn tool conditions, despite increased roughness, IF-UTS, and IF-CoF, primarily due to reduced adhesive wettability and penetration. Glueline delamination remained low and was not significantly affected by wood species or tool wear, demonstrating the effectiveness of the PUR adhesive in accommodating surface variability. Overall, all FJ lamellas exceeded industry standards for UTS and failure modes, confirming reliable bonding performance. This study highlights the importance of balancing tool wear and wood species selection in FJ manufacturing. Moderate tool wear may be beneficial for DF, while maintaining sharp tools appears critical for HF and WRC. The findings provide valuable insights for optimizing machining strategies and improving the quality and consistency of structural FJ products in the wood industry.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/91227
note: INVESTIGATION OF THE EFFECT OF TOOL WEAR AND WOOD SPECIES ON SURFACE QUALITY AND PERFORMANCE OF FINGER-JOINT by Shiqing Li B.Sc., The University of British Columbia, 2023 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Forestry) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) May 2025 © Shiqing Li, 2025 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the thesis entitled: Investigation of the Effect of Tool Wear and Wood Species on Surface Quality and Performance of Finger-Joint submitted by Shiqing Li in partial fulfilment of the requirements for the degree of Master of Science in Forestry Examining Committee: Julie Cool, Associate Professor, Forestry, UBC Supervisor Gregory Smith, Professor, Forestry, UBC Supervisory Committee Member William Nkeuwa, Application Engineer, Engineered Wood, Henkel Supervisory Committee Member Xiaoliang Jin, Associate Professor, Mechanical Engineering, UBC Additional Examiner iii Abstract Finger-jointed (FJ) lamellas are widely used in mass timber where bonding performance is critical for structural reliability. However, tool wear during FJ can affect wood surface characteristics, potentially affecting adhesive behavior and joint strength. In this study, Coastal Douglas-fir (DF), Hem-Fir (HF), and Western Redcedar (WRC) were machined using freshly sharpened and worn cutting tools and bonded with a polyurethane (PUR) adhesive to evaluate changes in surface topography, surface energy, adhesive wetting, ultimate tensile strength (UTS), and initial friction properties. The findings indicate that worn tool increased surface roughness (SA, SP, SV) for all wood species, which improved initial friction strength (IF-UTS) and coefficient of friction (IF-CoF), enhancing pre-cured joint integrity and stability. For DF, tool wear also increased UTS due to im…
has type: Thesis/Dissertation
date issued: 2025-11
is shown at: 10.14288/1.0448984
language: eng
degree discipline: Forestry
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Cool, Julie
type: Text
identifier URI: http://hdl.handle.net/2429/91227