OPTIMIZING LAMINATION OF HYBRID THICK-WALLED CYLINDRICAL-SHELL UNDER EXTERNAL-PRESSURE BY USING A GENETIC ALGORITHM

The effects of thermal residual stresses, strains, and stacking sequen ces resulting from hybrid composite material system selection on the d esign of thick-walled cross-ply cylindrical shells are discussed by us ing a simple and accurate finite cylindrical element method formulated by Byon and Vinson [1]. It is seen that beneficial effects can be rea lized in the cylindrical shells by utilizing a hybrid of graphite/epox y and E-glass/epoxy material systems. An optimal stacking sequence of hybrid composite cylindrical shell is also proposed to give the smalle st value of tensile strain in the through-the-thickness direction. Thi s paper describes an optimal stacking sequence of a thick-walled cross -ply cylindrical shell laminated with hybrid composite materials deter mined by a genetic algorithm (GA) and shows that this method is useful for such an optimization problem.