DEVELOPMENT OF A FINITE-ELEMENT-BASED DESIGN SENSITIVITY ANALYSIS FORBUCKLING AND POSTBUCKLING OF COMPOSITE PLATES

A finite element based sensitivity analysis procedure is developed for buckling and postbuckling of composite plates. This procedure is base d on the direct differentiation approach combined with the reference v olume concept. Linear elastic material model and nonlinear geometric r elations are used. The sensitivity analysis technique results in a set of linear algebraic equations which are easy to solve. The procedure developed provides the sensitivity derivatives directly from the curre nt load and responses by solving the set of linear equations. Numerica l results are presented and are compared with those obtained using fin ite difference technique. The results show good agreement except at po ints near critical buckling load where discontinuities occur. The proc edure is very efficient computationally.