The Elasticity of Plywood

THE increase in speeds of modern aircraft types has brought with it many stiffness criteria for the prevention of flutter, entailing an accurate estimate of the stiffness and rigidity of structural parts, and if the skinning of such plywood stressed skin units as fuselages, wings, and control surfaces is to be of reasonable weight, and the relevant Air Ministry requirements are to be simultaneously satisfied, it becomes essential that more rigid methods of stiffness estimations of plywood panels should be employed than has been done hitherto. The difficulties in getting theory and practice to agree are many and may be enumerated as follows: