Sensitivity analysis and optimal design of geometrically non-linear laminated plates and shells

A high order shear deformation theory is used to develop a discrete model f or the sensitivity analysis and optimization of laminated plate and shell s tructures in non-linear response. The geometrically non-linear analysis is based on an updated Lagrangian formulation associated with the Newton-Raphs on iterative technique, which incorporates an automatic are-length procedur e. Fiber orientation angles and vectorial distances from middle surface to the upper surface of each layer are considered as the design variables, Dif ferent objectives, such as generalized displacements at specified nodes, vo lume of structural material, and limit load, and constraints of displacemen t and stress failure criterion are considered. The design sensitivities are evaluated analytically and are compared with sensitivities evaluated by th e global finite difference. Numerical examples are given to show the accura cy of the proposed model in the non-linear response and the corresponding d esign sensitivity analysis, and to show the applicability in the optimal de sign. (C) 2000 Elsevier Science Ltd. All rights reserved.