A.R Ghasemi - Ph.DDepartment of Mechanical Engineering, University of Kashan, Kashan, 87317-51176, Iran
M.H Hajmohammad - Ph.DDepartment of Mechanical Engineering, University of Kashan, Kashan, 87317-51176, Iran
E Ghaffari - Department of Mechanical Engineering, University of Kashan, Kashan, 87317-51176, Iran

In the present research, mass optimization of grid stiffened composite shell under external hydrostatic pressure has been investigated. At first, mass function as an objective function has been presented. Subsequently, buckling analysis of grid stiffened composite shell has been done to determine constraint function of optimization. For optimization process, some parameters can be used to increase mechanical performance of grid stiffened composite shell. The quantity of stiffeners, cross section area and the angle of stiffener are the variables which have been used to minimize mass by considering buckling criteria. Genetic algorithm has been used to reach optimal design of the grid stiffened composite shell. The results show that optimization problem has been converged in the 10 generations. Finally, the best model which has the minimum mass and satisfied buckling pressure has been presented.

Optimization, buckling pressure, grid stiffened composite shell, genetic algorithm