Graduate Thesis Or Dissertation

 

Non-destructive evaluation of veneer using optical scanning and ultrasonic stress wave analysis systems Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/gt54kq420

Descriptions

Attribute NameValues
Creator
Abstract
  • Non-destructive commercial ultrasonic grading provides laminated veneer lumber (LVL) manufacturers a means for sorting veneer based on average ultrasonic propagation time (UPT) and/or average dynamic modulus of elasticity (MOEd). While this may provide reliable estimations of modulus of elasticity (MOE), little is known about the influence of veneer defects on strength properties of veneer and LVL. It was hypothesized that inclusion of veneer defect and growth ring pattern measures, obtained via optical scanning, would improve veneer and LVL static tensile MOE and strength (Ft) property predictions. Non-destructive and destructive testing on Douglas-fir (Pseudotsuga menziesii) veneer and LVL was performed to evaluate improvements in veneer and LVL tensile MOE and Ft property predictions. Various models based solely on density, optical, and ultrasonic system measures, as well as various combinations of systems measures, were developed for individual veneer and LVL property predictions. The integration of optical and ultrasonic measures (i.e., combined system model) best explained the variation in veneer static tensile MOE and Ft. The combined system model best predicted average LVL static tensile MOE. LVL static Ft was best predicted by using overall average veneer measures comprising the entire LVL material, rather than the average of individually predicted veneer Ft used in assembling the LVL. Specifically, the combined system model, which included various specific average defect, growth ring pattern, and MOEd measures comprising the LVL material, best explained the variation in LVL static Ft values (R2 = 0.65) as compared to all other models. Results from this study suggest improved veneer and LVL Ft predictions can be achieved by integrating the existing ultrasonic and optical systems already existing in many manufacturing facilities. Additionally, the optical model which included average defect, growth ring, and density measurements within the LVL material better explained the variation in LVL static Ft values (R2 = 0.58), as compared to the MOEd (R2 = 0.52) and UPT (R2 = 0.31) models. As a result, the developed optical system showed promise as a suitable veneer grading system. A need was identified for future research on optically grading full-size veneer sheets and manufacturing and testing full-size LVL billets.
License
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Replaces
Additional Information
  • description.provenance : Made available in DSpace on 2009-05-13T22:58:10Z (GMT). No. of bitstreams: 1 DeVallance_dissertation.pdf: 2489750 bytes, checksum: a7e5fdae370b767532295b03a87d337a (MD5)
  • description.provenance : Submitted by David DeVallance (devallad@onid.orst.edu) on 2009-05-08T23:12:08Z No. of bitstreams: 1 DeVallance_dissertation.pdf: 2489750 bytes, checksum: a7e5fdae370b767532295b03a87d337a (MD5)
  • description.provenance : Approved for entry into archive by Julie Kurtz(julie.kurtz@oregonstate.edu) on 2009-05-13T16:07:50Z (GMT) No. of bitstreams: 1 DeVallance_dissertation.pdf: 2489750 bytes, checksum: a7e5fdae370b767532295b03a87d337a (MD5)
  • description.provenance : Approved for entry into archive by Linda Kathman(linda.kathman@oregonstate.edu) on 2009-05-13T22:58:10Z (GMT) No. of bitstreams: 1 DeVallance_dissertation.pdf: 2489750 bytes, checksum: a7e5fdae370b767532295b03a87d337a (MD5)

Relationships

Parents:

This work has no parents.

In Collection:

Items