Analytical Solution For Composite Stiffened Panel Under Out-of-plane Load

The current work concerns development of an analytical solution for calculation of stiffened composite panels.The stress-strain state of a flat rectangular multilayer panel made from polymer fibrous composite materials supported by a longitudinally-transverse set of stiffeners and a flat rectangular composite panel with an asymmetrical thickness package structure is investigated.The panels are considered under the action of an arbitrarily distributed transverse load and a thermal loading.The solution of the problems is based on hypothesis of thin plate theory.The innovation of the research is provided by the solution of a boundary-value problem for an equilibrium equation of eighth order when the tension-compression,bending and torsion problems are considered jointly in double trigonometric series.Symbolic integration method is implemented to get the equilibrium equation.Influence of stiffeners’ stiffness in different directions on the stress-strain state of a panel is analyzed.Applicability limits of Kirchhoff’ theory for calculation of anisotropic stiffened panels are determined.The proposed analytical solution can be used for further optimization procedure in a strict mathematical formulation.The conducted study is meaningful for application in aircraft design since it reduces and optimizes weight characteristics of composite structures.The suggested analytical solution is the simple and rapid approach for calculation since it minimizes calculation time and eliminates a need for model simulation.