Technological Analysis Of A Morphosis Technique For Free-Form Surfaces And Mesh Generation

Nowadays, single layer lattice shell structure is widely used in large-span space structures because of the features of light weight,large stiffness and rich modeling styles. The current research concerning the modeling of single-layer reticulated shells has been relatively mature, including various analytic surface and free-form surface, constructed in many forms of surface mesh. However, there is much less research regarding for the advanced development of modeling for the internal grid.This essay will illustrate reconstructed of single-layer reticulated shell within the grid model. The single-layer reticulated shell structure will be used as the main framework, after which the secondary structure would be made within the grid construction using loop subdivision method. Meanwhile, such secondary structure will be optimized in accordance with the sensitivity of strain energy and the mechanics performance formed through geometric relationships will be improved. In the end, the single-layer reticulated shell with the relationship between primary and secondary structure will be integrated by composing of optimization secondary structure and main framework. The methods will be depicted as follows:This method is based on the selection of mainframe structure. 1. The selection of mainframe structuresThis method is based on the selection of mainframe structure. Loads produce direct effect on the secondary structure, passing through the secondary rod to the mainframe structure, and then passed by the main lever to the ground. Therefore, mechanical rationality of the mainframe structure is particularly important. Moreover, as a building’s main support system, the mainframe structure plays a decisive role in overall shape of the building. To select the form of structure, aesthetic sense to the main framework is equally essential. In this paper, single-layer latticed shell optimized with genetic algorithm is set as the main framework and the process will be discussed in detail.2. Construction of the secondary structureIn this paper, computer graphics Loop subdivision method is going to be applied to the construction of the secondary structure of the grid. According to the selection of grid by the central control point, dividing grid roughly, mesh subdivision and a series of operations, the initial model of the secondary structure will be built. Since the Loop subdivision method is based on the geometric generation, it is necessary to optimize the mechanical properties. By adjusting the node Z coordinate, the strain energy of the structure will be adopted as optimization objective function and therefore be reduced to a minimum level in order to form a secondary grid structure of both aesthetics and reasonable force.3. The integrated approach of primary and secondary structureAccording to the mainframe mesh situation, the shape of internal grids is further developed to construct the secondary structure. Primary and secondary structures are connected on the basis of load conversion relation. After creating secondary structure for each grid of the primary structure, the primary and secondary structures are assembled and formed a single-layer latticed shell. In the process of constructing the secondary structure, changes of the strain energy of the whole structure will be analyzed and the rationality of this method will be discussed.Using this method to establish a single-layer lattice shell with primary and secondary structural has advantages of reasonable force, novel form, attractive appearance as well as the strong visual impaction. Construction of the secondary structure of the mainframe structure meshes units operate independently, so the shape, size and distribution of the grid are not subjected to restrictions. This approach is well-adapted and can be applied widely, its secondary structure can be constructed for reasonable network shell. Meanwhile, in the process of constructing multiple studies, the strain energy of overall structure changes in similar trend. The method has stable calculated Performance and high reliability. It is believed that this method of modeling of the single-layer latticed shells will open up a whole new direction.