Optimum spacing design of grillage systems using a genetic algorithm

In this study a genetic algorithm based method is developed for the optimum design of grillage systems. The algorithm not only selects the optimum sec tions for the grillage elements from a set of standard universal beam secti ons, but also finds the optimum spacing required for the grillage system. D eflection limitations and allowable stress constraints are considered in th e formulation of the design problem. Due to the fact that grillage elements are thin walled sections, warping plays an important role in their design, particularly, when they are subjected to significant torsional loading. Th e algorithm developed has the flexibility of including or excluding the eff ect of warping in the design process. Grillage structures are designed for uniformly distributed loading. The optimum spacings are determined both con sidering and not taking into account the effect of warping in the design. T he comparison of the results shows that inclusion of warping in the design process has a significant effect on the optimum spacing. (C) 2000 Civil-Com p Ltd and Elsevier Science Ltd. All rights reserved.