Bending Performance of Spliced, Nail-Laminated Posts With Edge Reinforcement

Two groups of 3-ply laminated posts were constructed from 2 x 6 visually graded No. 1 Southern Pine lumber. One group of 23 posts was constructed without splice joints with the boards running continuously along the full length of each post. The second group of 23 posts was constructed by first cutting each board in two and splicing it back together forming butt joints without changing the grain orientation of the board. Two toothed connector plates 1 1/2 inches wide by 39 inches long pressed into the narrow edge of each board were used to splice the board back together. The individual bending stiffness about the strong axis of each board was tested before and after making the splice joint. The average gain in bending stiffness for each board that was cut in two and spliced back together was 20.5%. The spliced boards were then nailed laminated together to form a 3-ply post. All posts were loaded with two point loading to determine ultimate bending strength. At the 5% exclusion value, assuming a normal distribution, the spliced posts obtained 82% of the ultimate mid span bending moment of the control group of unspliced posts. Four inch sections of the toothed plate were tested to determine the load-slip relationship of the plates when they were pressed into the edges of 2 x 6 boards. The load-slip parameters derived from testing the 4 inch plate sections were used in a finite element program called FEAST to model the bending performance of the 23 posts that were spliced together with splice plates 39 inches long. FEAST accurately predicted the center span deflection of each spliced post with an average error of 3.5%.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Agricultural Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Kelley, Van C.

Contributors dc:contributor

• Riskowski, Gerald L.

• Engineering, Materials Science

Language dc:language

eng

Identifier

(MiAaPQ)AAI9921702

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/86093