Elastic Instability of Rectangular Sandwich Panel of Orthotropic Core With Different Face Thicknesses and Materials

This paper treats the instability of rectangular sandwich panels with nonisotropic cores and faces of different materials or thicknesses. The simply supported panel is loaded with a uniform edge compression. The solution is expressed in terms of a major buckling coefficient, given as the ratio of the critical lateral buckling load to the critical cylindrical buckling load, which is a function of several nondimensional parameters. A single family of curves shows the buckling behavior for all parameters. The effect of a moderate temperature differential between the two faces can be approximately considered by modifying their moduli of elasticity in accordance with their temperature levels. Besides the regular panel instability, a zone of core shear instability is determined and discussed in detail. Numerical examples are presented to illustrate the application of the analysis.