Research On Parametric Design Of Polyhedral Spatial Structure Based On Revit

The long-span space structure represented by the National Aquatics Center “Water Cube” has developed rapidly in China,with a large number of buildings,rich structure types and increasing levels of innovation.The polyhedral spatial structure has the characteristics of superior mechanical properties and unique structural form.It has the advantages of high repetition,less node types and less joined members.Only four bars are intersected at each node in the structure and the mathematical characteristics of filling the three-dimensional structure with the minimum number of nodes and rods are obtained.The complexity of the polyhedral spatial structure determines that its design must adopt parametric design.Revit,as an important platform for BIM technology,provides a good support for this.The spatial structure is a unique “self-growth” modeling idea,which is different from most of the current model software “building blocks” modeling method.But the current modeling method based on Revit does not involve the polyhedral spatial structure which is a classic structure type.Based on the second development technology of Revit,this paper proposes a new method for parametric modeling of polyhedral spatial structure with semi Weaire-Phelan polyhedron as the basic unit.Compared with the previous method,it simplifies the programming idea,improves the flexibility of modeling and enriches the information output function of the model.The main works of this paper are as follows:(1)Based on the second development technology of Revit,combined with the mathematical theory of semi Weaire-Phelan polyhedron,through the parameter control method,the three-dimensional modeling of the basic unit and basic combination of semi Weaire-Phelan polyhedron in Revit project file is realized.(2)Based on the new API function provided by Revit,a new modeling method is proposed for the limitations of existing polyhedral spatial structure modeling methods.The programming method of the new method is simpler.With the newly added building profile control parameters,not only can the building shape be flexibly controlled,but also the modeling process of the overall structure of the building can be directly controlled.(3)Design and implement a check algorithm for point,line and surface repeating elements to ensure the uniqueness of model nodes and members,and to ensure the accuracy and practicability of the modeling results.(4)The output function of the key information of the model is realized.The output data files also take into account the interface requirements with other third-party software.This paper uses the “Water Cube” as a model to realize the modeling of the spatial structure of semi Weaire-Phelan polyhedron.After verification,the modeling plug-in designed in this paper can realize the preliminary modeling for the class of “Water Cube” structure(without the model change after structural optimization).At the same time,the applicability of the modeling method is verified by a customized engineering case.