Equivalent Bending Stiffness of Laminated Composites Tubes With Polygonal Cross-Sections

Simple analytical solutions are developed for efficient computation of equivalent bending stiffness and ply stresses for n-sided regular polygonal cross-sections. The cross-sections investigated includes triangle, square, pentagon and hexagon for 3, 4, 5 and 6 sides, respectively. The analytical solution, based on Classical Lamination Theory, transformation matrices and parallel axis theorem, computes the in-plane stresses at each ply level of the laminate. Good agreement in comparison of results between analytical solutions and finite element results from ANSYS was achieved. This method represents an efficient tool for design engineers to perform parametric studies during the preliminary design phase.