Virginia Polytechnic Institute and State University, Blacksburg, VA
Despite the tailorability of laminated fiber composites, the tendency has been to use lay-ups that more closely approximate an isotropic material. These so-called quasi-isotropic lay-ups are used so the structure or component fabricated from them can withstand loads oriented in many directions or perhaps accommodate an unexpected loading. Since there is so much literature associated with predicting the static and dynamic response of isotropic beams, plates, and shells, particularly in table look-up format, the question arises as to the applicability of these tabulated results to members made from quasi-isotropic composite materials. The purposes of this paper are: (1) to indicate the degree of isotropy exhibited by a certain quasi-isotropic sandwich construction, (2) to verify that standard isotropic strength-of-materials formulas can be used to predict the response of these quasi-isotropic components for certain loadings, and (3) to present numerical data for a particular material system. It is felt that even though the results are presented for a sandwich construction, they can be extended to quasi-isotropic lay-ups in general.
Paper ID: CTR10704J