Analysis of Composite Structures Using the 3-D Global/3-D Local Method

A global/local (G/L) method is presented for the analysis of composite structures that need to be modeled in 3-D. The method employs a modified version of effective stiffnesses specification at the global level such that both extensional and flexural behavior of symmetric composite structures are replicated. A numerical verification problem of a quasi-isotropic composite cantilever beam with mid-beam cut-outs under edge pressure load is used to determine the efficiency and accuracy of the proposed 3-D Global/3-D Local method. The effect of global stiffness specification on the local solution is explored. Results indicate that the proposed G/L method may be over 20 times more efficient while the error in both in-plane and interlaminar stresses are less than 5% when compared to the predictions of a highly refined finite element model used as a control.