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

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): A. Alshaya; John Hunt; R. Rowlands
    Date: 2016
    Source: Journal of Engineering Mechanics. Vol. 142(11). 10 p.
    Publication Series: Scientific Journal (JRNL)
    Station: Forest Products Laboratory
    PDF: Download Publication  (3.0 MB)


    Stress and strain concentrations and in-plane and out-of-plane stress constraint factors associated with a circular hole in thick, loaded orthotropic composite plates are determined by three-dimensional finite element method. The plate has essentially infinite in-plane geometry but finite thickness. Results for Sitka Spruce wood are emphasized, although some for carbon-epoxy composites are included. While some results are similar to those for isotropy, there are significant consequences due to material orthotropy. Maximum stress and strain concentration factors occur at midplane for thin plates but closer to the external traction-free surfaces for thick plates. These factors decrease as the plate surface is approached and reach lower values unrepresentative of the maximum values. Differences between the mid-plane and/or maximum and surface stress or strain concentration factors in Sitka Spruce, range from 8% if the wood grain is parallel to the vertically applied load to 15% when the grain is perpendicular to the load. These values exceed those typically reported for isotropic materials. Stress and strain concentration factors tend to differ in magnitude from each other. The combination of high local stresses and directional strength dependency of orthotropic materials can be particularly important. That maximum stress and/or strain concentrations in thick plates occur on other than the external plate surfaces where they are most readily measured is technically significant. The E11/E22 ratio Sitka Spruce exceeds that in the carbon composite by 60%. However, when loading parallel to the strong/stiff directions, the plane-stress tensile stress concentration factors of the two materials are comparable to each other.

    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.


    Alshaya, A.; Hunt, J.; Rowlands, R. 2016. Stresses and strains in thick perforated orthotropic plates. Journal of Engineering Mechanics. 142(11). 10 p.


    Google Scholar


    Holes, Thick plates, Three-dimensional stresses, Three-dimensional strains, Constraint factors, Orthotropy, Sitka Spruce, Carbon/epoxy composite.

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page