Efficient Higher-Order Shell Theory for Laminated Composites with Multiple Delaminations

Abstract

A higher-order zigzag theory has been developed for laminated composite shells with multiple delaminations. General tensor-based formulation is developed for arbitrary curved shell with exact geometric description. A laminated shell theory with multiple delaminations for general lamination configurations is obtained by superposing a cubic varying displacement on a zigzag linearly varying displacement. The von Karman nonlinearity is included in the formulation for the potentialities of addressing problems requiring geometric nonlinearity such as large deflection and postbuckling problems. When top and bottom surface transverse shear stress free conditions and interface transverse shear continuity conditions including delamination interfaces are imposed the displacement of the minimal degrees of freedom is obtained. The proposed displacement field can systematically handle the number, shape, size, and locations of the delaminations. Through the variational principle, equilibrium equations and variationally consistent boundary conditions are obtained. To assess the accuracy and efficiency of the present theory, the linear buckling problem of cylindrical shell with multiple delaminations has been analyzed. The higher-order zigzag theory should work as an efficient tool for analyzing the behavior of composite laminated shells with multiple delaminations.