A Semi-Analytical Approach for the Analysis of Variable-Stiffness Panels with Curvilinear Stiffeners

A semi-analytical method is developed for the analysis of composite stiffened panels, where stiffness variability is achieved through a combination of fiber steering and curvilinear stringers. The approach relies upon a 2D plate model for the skin and a 1D beam description for the stiffeners, according to first-order shear deformation theory. The approach is developed in the framework of a displacement-based formulation, where Legendre polynomials are used for approximating the displacement field, and the Ritz method is used for the solution strategy. The resulting tool is characterized by its excellent computational efficiency, and allows problems in free-vibrations, buckling and thermal buckling to be solved with reduced effort. The quality of the results is assessed by an extensive set of comparison against results from the literature, demonstrating the potential of the tool as a means for performing preliminary parametric studies for these variable-stiffness, variable-geometry structures.