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

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dc.contributor.advisor Funck, James W.
dc.creator DeVallance, David B.
dc.date.accessioned 2009-05-13T22:58:10Z
dc.date.available 2009-05-13T22:58:10Z
dc.date.copyright 2009-04-24
dc.date.issued 2009-04-24
dc.identifier.uri http://hdl.handle.net/1957/11580
dc.description Graduation date: 2009 en
dc.description.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. en
dc.language.iso en_US en
dc.subject Veneer en
dc.subject Laminated Veneer Lumber en
dc.subject Optical Scanning en
dc.subject Ultrasonic Scanning en
dc.subject Douglas-fir en
dc.subject Non-destructive Evaluation en
dc.subject.lcsh Veneers and veneering en
dc.subject.lcsh Quality control -- Optical methods en
dc.subject.lcsh Optical scanners -- Design and construction en
dc.subject.lcsh Ultrasonic testing en
dc.title Non-destructive evaluation of veneer using optical scanning and ultrasonic stress wave analysis systems en
dc.type Thesis/Dissertation en
dc.degree.name Doctor of Philosophy (Ph. D.) in Wood Science en
dc.degree.level Doctoral en
dc.degree.discipline Wood Science en
dc.degree.grantor Oregon State University en
dc.contributor.committeemember Atre, Sundar
dc.contributor.committeemember Gupta, Rakesh
dc.contributor.committeemember Reeb, James
dc.contributor.committeemember Rochefort, Willie

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