Banner for LabNotes
From Lab Notes
Contact Information
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53726-2398
Phone: (608) 231-9200
Fax: (608) 231-9592
Email

 

You are here: FPL Home  / Information Products & Services  / Publications

Requested Product

Title: The influence of juvenile wood content on shear parallel, compression,and tension perpendicular to grain strength and mode I fracture toughness of loblolly pine at various ring orientation

Source: Forest products journal. Vol. 58, nos. 7/8 (July/Aug. 2008): Pages 89-96

Author(s)Kretschmann, David E.

Publication Year: 2008  View PDF »

Category: Journal Articles

Abstract: Forest products from improved trees grown on managed plantations and harvested in short rotations will contain higher proportions of juvenile wood than in current harvests. More information is needed on the influence of juvenile wood on lumber properties. Most information developed to date has concentrated on ultimate tensile stress, modulus of rupture, and modulus of elasticity. This paper shows for this sample of loblolly pine three-dimensional surfaces fit to test results for shear stress parallel to the grain, compression and tension stress perpendicular to the grain, and mode I fracture toughness for various percentages of juvenile wood content and ring orientations. The properties of more than 340 small specimens for each property tested made from clear wood taken from lumber produced from logs harvested in a 28-year-old fast-grown plantation of loblolly pine in North Carolina were determined. Three-dimensional polynomial surfaces dependant on juvenile wood content and ring orientation ere fit to the data. The average strength of all properties decreased with increasing amounts of juvenile wood in the cross section. Shear strength was insensitive to annual ring orientation and seemed to be strongly dependant on reductions in density caused by increased juvenile wood content. Compression and tension perpendicular to the grain strength and stiffness and mode fracture toughness were very sensitive to juvenile wood content and annual ring orientation.

Keywords: Modulus of elasticity, elasticity, loblolly pine, compression testing, mechanical properties, juvenile wood, wood, lumber, shear, tree rings, wood strength, shear strength, compression perpendicular to grain, tension perpendicular to grain, tensile strength, loblolly pine, strength

File size: 320 kb(s)

This publication is also viewable on Treesearch:  view
RITS Product ID: 26374
Current FPL Scientist associated with this product
Kretschmann, David E.
Research General Engineer
  

Additional items that might interest you
View the video celebrating FPL's 100 years of public service in 2010, from the producers of the Greatest Good....view

Research Highlights from FPL....view

Termite Eradication: A search for the Holy Grail.... view

Moisture Management in Residential Construction Series videos...view

Wood Floor Systems in Residential Construction Series videos....view
- FPL's Mission and Strategic Plan -

FPL's mission is to identify and conduct innovative wood and fiber utilization research that contributes to conservation and productivity of the forest resource, thereby sustaining forests, the economy, and quality of life. ... ..more »

- FPL Research Emphasis Areas -
Advanced Composites

As an integral part of the FPL mission, we improve the long-term sustainability of our Nation's forests by creating valuable composite products from biobased materials ... ..more »


Advanced Structures

The FPL has been in the forefront of wood-frame housing research since 1910 and has long been recognized as a world leader in such housing-related areas as engineered wood ... ..more »


Forest Biorefinery

We all know the compelling reasons that the United States needs to reduce its dependence on fossil fuels. Historically, the greatest increases in energy demand have been for transportation fuels ... ..more »


Nanotechnology

A leader in wood products research for over a century, the FPL is positioning itself to become the lead Federal research facility for the application of nanotechnology in forest products ... more »


Woody Biomass Utilization

Forests in the United States contain a substantial amount of small-diameter, overstocked, and underutilized material.FPL research projects are exploring the potential of the small-diameter ... ..more »