Optimal design of glass grid shells with quadrilateral elements by means of a genetic algorithm

Abstract In this paper a constructional problem related to grid-shells design is approached as an optimisation problem and an evolutionary solution technique is proposed. The construction of glass grid-shells, when only four sides cladding elements are used, requires to check the planarity of each element, it means that the four corner points have to belong to the same plane. This requirement can be satisfied by generating the grid surface in specific ways (Schlaich and Bergermann [2]), but when the design involves truly free form shapes, a procedure of optimisation able to reduce the non planarity of each element can be applied. The proposed one is based on the use of a genetic algorithm and has been applied to a benchmark and to a real case, in order to evaluate the efficiency of the procedure and the goodness of the solution. Introduction The design of complexes structures involves not only complexes analyses and verifications but even the solution of constructional problems. Especially in free form architecture, when members and elements shapes are not regular, many manufacturing problems have to be solved, in order to make the construction efficient and to reduce costs. In recent years, due to the large diffusion of numeric control machine tools, the production problems transformed into design problems and a the process of manufacturing needs to be managed almost completely at the design time. The effect on architecture is the growth of free form projects, made possible by a strong industrialisation and prefabrication of the components, but non necessarily in the sense of a request of standardisation. Hence the design of free form architecture usually involves the search of optimal solutions of design problems and the development and use of robust and flexible computational tools, as the one presented in this paper, can give a significant contribution.