Abstract
This paper studies the optimization for inner rib's thickness of the shell structure of aluminum allow hollow extrusion by using genetic algorithm. In the optimization, total mass of the structure is minimized under the constraint conditions with respect to maximum deformations of the structure. The deformation of the structure is evaluated numerically by using the finite element analysis developed for tow-dimensional elasticity in the present study. In numerical calculations optimal design solutions are obtained for the structures by specifying the allowable maximum deflections of the structure, and the effect of the rib's thickness is studied from the numerical results obtained.
