Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

 Due to a lapse in federal funding, this USDA website will not be actively updated. Once funding has been reestablished, online operations will continue.


  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub

    Description

    Current procedures used to sort round timber beams into structural grades rely on visual grading methods and property assignments based on modification of clear wood properties. This study provides the technical basis for mechanical grading of 228 mm (9 in.) diameter round timbers. Test results on 225 round Engelmann spruce–alpine fir–lodgepole pine beams demonstrate the conservative nature of current timber strength assignments. A good correlation was obtained between static bending strength and static modulus of elasticity (MOE), and between bending properties and dynamic MOE determined in transverse vibration. Relationships were also developed between compressive strength parallel to grain, bending strength, and MOE by transverse vibration. The property relationships developed in this study were used to propose grading criteria consistent with procedures used with mechanically graded softwood dimension lumber. Estimated grade yields obtained using the proposed criteria show that significant increases in yield might be obtained for a specified set of allowable properties than is currently possible by visual grading alone.

    Publication Notes

    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

    Citation

    Green, David W.; Gorman, Thomas M.; Evans, James W.; Murphy, Joseph F. 2006. Mechanical grading of round timber beams. Journal of materials in civil engineering. (Jan./Feb. 2006): Pages 1-10

    Keywords

    Elasticity, compression, vibration, beams, wood

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page
https://www.fs.usda.gov/treesearch/pubs/22997