An Analysis Of Flexural Elastic Behavior Of 3-PLY Southern Pine Plywood


  • Evangelos J. Biblis
  • Jen-Ming Chiu


Two methods for predicting deflections of 3-ply plywood have been verified experimentally and compared. Both methods can predict accurately the total deflection, pure bending deflection and shear deflection even at a span-to-depth ratio 14:1 of 3-ply southern pine plywood. The approximate method predicts deflections with as much accuracy as the exact theoretical method. The approximate method has the advantage of being simpler in application, and it does not require the knowledge or determination of Poisson's ratios and values of pure modulus of elasticity for the core (ETR) required by the exact method. Both methods require accurate values of modulus of rigidity in "rolling shear" and/or an accurate value of the ratio GTR/GLR. It is suggested that values of GTR for all commercial species, used for production of structural plywood, be determined by an accurate method.


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