REDESIGN OF PLATES BY LARGE ADMISSIBLE PERTURBATIONS

The problem of structural redesign of plates for static deflection and modal dynamics objectives is formulated and solved by the method of l arge admissible perturbations. The perturbation approach to redesign i s first used to develop response equations for the objective plate des ign based on its specifications and the baseline plate design. The equ ations of the objective state are strongly nonlinear implicit expressi ons of the variable plate thickness. A large admissible perturbations algorithm is developed to solve the plate redesign problem and define the optimal objective state. The latter is reached incrementally with a prediction-correction scheme without repeated finite element analyse s. Systematic numerical applications in redesign of a cantilever plate of 216 degrees of freedom are used to investigate the effects of numb er of extracted modes and redesign variables. It is shown that the lar ge admissible perturbations theory can be used efficiently to redesign plates for multiple specifications that require changes to the baseli ne design and its response of the order of 100%.