Structural Optimization of Foam-Core and Honeycomb-Core Sandwich Cylinders under Axial Compression

摘要

Data for the optimum structural design of foam-core and squarecell-honeycomb-core sandwich cylinders under axial compression are presented in this report. For predicting the general mode of instability, the method recently proposed by Almroth is employed, which includes the effects of transverse shear deformations. This method also utilizes the upper and lower bounds to the critical buckling load, and an empirical factor applied to the difference between the two bounds. Although the data presented relate to sandwiches having facings of equal thickness and identical material the computer programs developed to generate these data are capable of analyzing sandwiches wherein the facings are dissimilar with respect to thickness and/or material. The computer programs are presented in appendixes, along with a summary of information on the shear moduli for various sandwich configuration. It is shown that practical foamcore and squarecell-honeycomb-core constructions are possible at low loading indexes which are more efficient than conventional construction involving rings and stringers of rectangular cross section. At high loading indexes, where the stresses in the sandwich facings approach the maximum permissible stress, these sandwich constructions show little superiority over conventional construction, and may even be less efficient. (Author)