A fixture is described for making normal-pressure tests of flat plates 5 inches in diameter in which particular care was taken to obtain rigid clamping at the edges. Results are give for 19 plates, ranging in thickness from 0.015 to 0.072 inch. The center deflections and the extreme-fiber stresses at low pressures were found to agree with theoretical values; the center deflections at high pressures were 4 to 12 percent greater than the theoretical values. Empirical curves are derived of the pressure for the beginning of permanent set as a function of the dimensions of the plate and the tensile properties of the material.

A theoretical and numerical analysis is presented for the elastic deflections and stresses of an initially flat circular plate with clamped fixed edge, under uniform normal pressure. In considering large deflection bending, i.e. deflections up to several thicknesses of the plate, we are led to two coupled partial differential equations which are given in the literature by Foppl and von Karman. We attempt an approximative solution of these equations by representing each of the unknown functions of these equations as a formal series of eigenfunctions. We choose the most natural set of eigenfunctions, the Bessel functions of index one, each of which individually satisfied all but one of the boundary conditions. We then calculate, by means of computer methods, deflection and stress results which turn out to be in strikingly good agreement with earlier theoretical and experimental results in the literature. All of this is accomplished with but a five or nine mode solution, which can be found with very little effort. (Author).

This book is concerned with the general theory of finite deflections of thin elastic plates and shells. The nature of the governing equations is such that deflections are essentially limited to several times the plate or shell thickness, in the spirit of the usual von Karman approximation. Finite deflections of laterally loaded rectangular plates with various edge conditions are treated in detail. The postbuckling behavior of ordinary and rib-stiffened rectangular plates subject to in-plane loads is also examined. The finite deflections of circular plates subject to axisymmetric lateral or in-plane loads are examined. Finite deflections of shallow shells in the form of curved panels subject to lateral load are studied on the basis of an approximate shell theory. The postbuckling behavior of cylindrical panels subject to various in-plane normal and shear forces is treated in detail. The finite-deflection buckling of circular cylindrical shells subject to axial compression, lateral loads, or torsion is examined with a consideration of the effects of initial geometric imperfections. Lastly, the finite-deformation buckling of spherical shells and spherical caps is treated by an approximate shell theory. The approximate theories are correlated with available experimental evidence wherever possible.