Effect of Polar Anisotropy of Wood Loaded Perpendicular to Grain
Publication: Journal of Materials in Civil Engineering
Volume 13, Issue 1
Abstract
This paper reports on an analysis and experimental verification of the effect of cylindrical anisotropy of softwood loaded in the radial r and tangential t growth plane, i.e., perpendicular to grain. This off-axis loading mode is especially design-relevant for curved and tapered glulam beams. The very low shear stiffness in the r,t on-axis growth plane, together with a complex shear coupling effect in polar coordinates, contributes essentially to extremely variable off-axis strain and stress fields. Thus far, no explicit empiric proof exists for these effects with considerable consequences on damage-relevant stresses. The exemplary off-axis investigations were performed with a cross-sectional slab of a spruce board loaded in tension parallel to the longer edges. True on-axis stiffnesses were determined for the simulations from two on-axis specimens cut from the test volume. Throughout a good agreement between the finite-element predictions and the measured results was obtained. The experiments, for example, proved that off-axis strains parallel and normal to load axes may vary along specimen length by factors of about 4.5 and 9, respectively.
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Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 13 • Issue 1 • February 2001
Pages: 2 - 9
History
Received: Apr 22, 1999
Published online: Feb 1, 2001
Published in print: Feb 2001
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