Pre-buckling and Buckling Analysis of Variable-Stiffness, Curvilinearly Stiffened Panels

This work illustrates a fast numerical approach for analyzing the pre-buckling and buckling response of innovative panel configurations for aerospace structures. Specifically, the approach allows composite panels with variable-stiffness skins and stiffened by curvilinear stringers to be studied in a fast yet accurate manner. The method of Ritz is applied in conjunction with first-order theories for modeling the skin and the stiffeners, the former described referring to Mindlin plate theory, the latter to Timoshenko beam model. Due to the excellent convergence properties of the approach, pre-buckling stress distributions can be captured with reduced effort. Similarly, accurate buckling predictions can be obtained with relatively few degrees of freedom, much less with respect to typical models relying upon the use of finite elements. Results are presented for a number of test cases from the literature, illustrating the potential of the proposed approach as a mean for performing preliminary studies with reduced computational effort.