LOCALIZED FORMULATIONS FOR THICK SANDWICH LAMINATED AND COMPOSITE STRUCTURES

A ''sandwich'' panel under axial compressive loading, is studied over its post-buckling range. Alternative formulations were developed to co ver solutions other than the deflection shape given by the classical R ayleigh-Ritz analysis. General elasticity principles are used to deriv e the total potential energy function in terms of the displacement fie ld. Given a constant modal amplitude displacement field, which is intr oduced in the total potential energy function, the results are discuss ed having as background models studied earlier. Techniques for the ana lysis of localized solutions are presented with reference to the study of the beam on nonlinear elastic foundation. The concepts of localiza tion are introduced by using dynamical analogy and the double scale pe rturbation method and applied to the sandwich panel, to derive the gov erning amplitude modulation equations. The resulting formulations are discussed using some examples, and by solving analytical and numerical ly the amplitude differential equations.