Application Of Cellular Automata In The Shape Optimization Of Single-layer Shell Structure

Shell structure has many properties, such as reasonable structure, beautiful shape, large span, light weight, good mechanical, so widely used in train station, gymnasium, theater, museums and other public buildings. In recent years, our country has a large number of representative grid shell appears ceaselessly, fully embodies the structure has strong vitality.Shape optimization design of single-layer reticulated shell structure is an very important step. Proper shape can make structure stress evenly, has high rigidity, small deformation and high stability. The single layer reticulated shell structure shape optimization problems were studied, establishes the bending moment minimum of overall structure (?)as the objective function of optimization method.In order to obtain different shell shapes, this paper established a cellular automata model of single-layer shell. In the model, applying the gravity reverse loading, single-layer shell start vibration deformation. Through the vibration of the shell deformation we obtained a series of different shell shapes. In contrast to these (?) values, choice of value minimum appearance as a new starting point, then release the internal force, make shell vibration from the new starting point search for the next extreme point. Eventually the (?) value reaches the minimum or the shell height is achieved the design requirements, the shape is that we need.In this paper,the parameters which were used in the shape optimization were analyzed. For example, the original shape, the moment of inertia, the elastic modulus, the wave velocity. On the results of numerical tests, this paper determine a reasonable value range.In order to verify the validity of the method in this paper, a shape optimization analysis of a single-layer shell in TianJin was made, and results were obtained. This paper studies the mechanical properties and the stability of shells before and after shape optimization.The results show that after the shape optimization of shell, with little change in shape, mechanical performance and stability are greatly improved, show that the optimization method is feasible.