| The dissertation research presents the theoretical and computational procedures that have been applied in the design of a special purpose computer program for computing static nonlinear response of laminated shell structures. A general formulation of the incremental equations of motion for laminated shell structures undergoing large displacement finite strain deformation is presented. These equations are based on the Lagrangian frame of reference, in which constitutive models of a variety of types may be introduced. The incremental equations are linearized for computational purposes, and the linearized equations are discretized using isoparametric serendipity finite elements. Computational techniques, including step-by-step incremental approach and the BFGS type iterative procedure, for the solution of nonlinear equations are also discussed in detail.; A fully nonlinear analysis for prediction of large deformation behavior of thick laminated composite shells and panels is presented. This research accounts for fully nonlinear strain-displacement relations, in contrast to the commonly used von Karman type nonlinear assumption. The formulation accounts for layerwise linear displacement distribution, in conjunction with large strain as well as large deflection/rotational behaviors. The fully nonlinear kinematic relations are employed in the present study so that stable equilibrium paths in the advanced nonlinear regime can be accurately predicted. |
