AN EXPERIMENTAL INVESTIGATION OF STRUCTURAL COMPOSITE LUMBER LOADED BY A DOWEL IN PERPENDICULAR TO GRAIN ORIENTATION AT YIELD AND CAPACITY

Type of Document Master's Thesis
Author Finkenbinder, David Edward
Author's Email Address davidfink@vt.edu
URN etd-09142007-121840
Title AN EXPERIMENTAL INVESTIGATION OF STRUCTURAL COMPOSITE LUMBER LOADED BY A DOWEL IN PERPENDICULAR TO GRAIN ORIENTATION AT YIELD AND CAPACITY
Degree Master of Science
Department Civil Engineering
Advisory Committee
Advisor Name Title
Dr. Daniel P. Hindman Committee Co-Chair
Dr. W. Samuel Easterling Committee Co-Chair
Dr. Joseph R. Loferski Committee Member
Dr. Surot Thangjitham Committee Member
Keywords

* Parallel Strand Lumber
* Laminated Veneer Lumber
* Capacity
* Monotonic Loading
* Wood Connections

Date of Defense 2007-09-04
Availability unrestricted
Abstract

The research summarized by this thesis was comprised of an experimental analysis of beams loaded perpendicular to grain at midspan by a bolted double-shear laterally-loaded connection. Connection specimens were loaded monotonically until capacity was reached. Variables of consideration included the loaded edge distance of the connection main member, the span:depth ratio of the main member, and the main member material. Southern pine machine-stress-rated (MSR) lumber, laminated veneer lumber (LVL), and parallel strand lumber (PSL) were the three material types included in the program.

Experimental results were compared with theoretical predictions from three models: the yield theory-based general dowel equations, which are currently the standard for laterally-loaded connection design in the U.S., and two models based upon fracture mechanics. All material property inputs required by the three models, were measured in the experimental program of this research and used to produce theoretical predictions. Comparisons were also made with respect to design values in the form of calculated factors of safety, over-strengths, and design factors of safety.

Test results and observed trends are provided for all connection and material property tests. Notable trends included failure by splitting for all connections at low loaded edge distances, and variable span:depth ratios generally having a negligible effect on both connection and model performance. In most cases, the general dowel equations were more accurate than the two fracture models, however it should be noted that all three models over-predicted connection capacity at low loaded edge distances.

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