An Analysis of Flexural Rigidity of 7-Ply Southern Pine Plywood Strips at Short Spans Parallel to Face Grain<sup>1</sup>
Abstract
Two methods for predicting deflection of 7-ply plywood strips in small span-to-depth ratios have been developed and presented together with experimental verification. These methods first require transformation of the cross section of 7-ply plywood into a hypothetical homogeneous cross section with grain direction of all plies parallel to span. With one method, shear deflection is calculated by equating the internal work with the external work of the transformed cross section. With the other method, shear deflection is calculated with an equation based on the assumption that shear deflections in any two similarly loaded beams of the same length, height, and moment of inertia are proportional to the summations of the shear stresses on their respective vertical sections.
Shear and total deflections of 7-ply plywood at short spans, predicted by both methods, are in good agreement with deflections obtained from actual tests.
References
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