Skip to page content
USDA Forest Service
  
Treesearch

Research & Development Treesearch

 
Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Northern
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help
 

Science.gov - We Participate


USA.gov  Government Made Easy


Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.
20090-6090

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

View PDF (2.7 MB bytes)

Title: Effect of elliptic or circular holes on the stress distribution in plates of wood or plywood considered as orthotropic materials

Author: Smith, C. B.;

Date: 1944

Source: Report / Forest Products Laboratory (U.S.)-no. 1510. Madison, WI : U.S. Forest Service, Forest Products Laboratory, 1944: 25 pages.

Publication Series: Miscellaneous Publication

Description: This is a mathematical analysis of the stress distribution existing near a hole in a wood or plywood plate subjected to tension, as, for example, near holes in the tension flanges of wood box beams. It is assumed that the strains are small and remain within the proportional limit. In this analysis a large, rectangular, orthotropic plate with a small elliptic hole at the center is subjected to a uniform tension along two opposite edges. By taking equal axes for the elliptic hole, the theoretical stress analysis shows that for a circular hole in a plain-sawn plate of Sitka spruce a maximum tensile stress of 5.84S is attained, S. being the uniform tension applied in the direction of the grain. This maximum stress occurs on the edge of the circular hole at the ends of the diameter perpendicular to the direction of the uniform tension. Although this stress concentration may be greater than that found in isotropic materials, it is much more sharply localized and is relieved by plastic flow when the stress exceeds the proportional limit. For the reader who does not wish to follow the mathematical details of this report, the formula for computing this maximum stress for wood or plywood and an explanation of the constants involved is given in the appendix. The formula has not been confirmed by an extensive series of tests, but it was found to be in reasonably satisfactory agreement with the only test made. It is also demonstrated that for the Sitka spruce plate mentioned the maximum shear stress attained is 0.71S (fig. 5). The stress function from which these formulas for the orthotropic case are obtained is shown to reduce to the well-known stress function for the isotropic case.

Keywords: Plywood, strength, mathematical models, analysis, stresses

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.

XML: View XML

Citation:


Smith, C. B. 1944. Effect of elliptic or circular holes on the stress distribution in plates of wood or plywood considered as orthotropic materials. Report / Forest Products Laboratory (U.S.)-no. 1510. Madison, WI : U.S. Forest Service, Forest Products Laboratory, 1944: 25 pages.

 


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.