An Elasticity Solution of Angle-Ply Laminated Composite Shells Based on a Higher-Order FE Analysis

In the case of advanced light weight material applications, the design of such components, in many cases, are based on applied surface tractions These surface loads can be caused by various means. When wind effects are present these tractions can be due to pressure, suction or drag. In the case of underwater applications, hydrostatic pressure and friction caused by moving against water current needs to be considered in the design. These are some of the traction load applications, a design engineer has to deal with in his advanced material applications. In contrast to the conventional materials, the modern structures made of highly directional dependent material properties, respond the applied loads and environment in an unpredicted way, so that, a detail analysis and design is always necessary. Hence in the present study a higher-order shear deformation formulation is developed to calculate the distribution of stresses accurately in angle-ply laminated shells of revolution. In this work the state of strain and stress at any point in the shell laminate are treated without any assumptions in the displacement fields in any direction. A Lagrange multiplier constraints are introduced into the formulations to enforce the surface traction conditions. The calculated displacements and stress distributions can be used to study the material failure, interface stresses and delamination etc. This analytical procedure also become very useful in the cases where a more attention is needed in the properties in the thickness direction of the laminate. A set of numerical examples are given using the FEM based on derived formulation.