Coupling Facade and Structure

Traditional approach for engineering the facade is building an isolated analysis model. However, it inhibits a dynamic design process where architects and engineers’ decision impact each other. Specialty facade structure, in particular, requires numerous design iterations, making engineering analysis a tedious process. Coupling the facade and structure together utilizing digital workflow provides an effective medium for architects and engineers to collaborate, achieving a workable solution while fulfilling the aesthetic vision.

The Minnesota United Soccer Stadium in St Paul, MN was a perfect example for which the analysis model is set up combining both facade and structures. Using digital workflow the design team of architects, engineers and fabricators were able to collaborate on a unique project. The geometry of the steel structure supporting a tensile skin was iteratively adjusted to ensure the performance of the fabric could be met while still maintaining the architectural aesthetic required by the design team. Key to this process was the utilization of digital workflow and tools that allowed engineering data to be passed to the architect to inform the design geometry, and a feedback loop set up where design could react to engineering data. A key design parameter was for the tensile structure to be able to "breath" with the structural supporting steel structure under thermal loading. Thus the facade, secondary structure and primary is completely coupled stiffness-wise between one another. Advanced digital work flow including custom-written Grasshopper component accessing analysis software’s API (application programming interface) was utilized to understand this behavior. It was a successful collaboration between architect, engineer and fabricator to deliver a structurally holistic building envelope.