Form-Finding of Architectural Knitted Tensioned Structures

Abstract

This study discusses the form-finding process of tensile structures and specially knitted tensioned structures. The performance of different plugins in Grasshopper is investigated for behavioral simulation of architectural knitted tensioned structures. Whereas multi-directionality and flexibility are the main characteristics of knitted textiles and allow these materials to be used to develop more complex architectural shapes, such characteristics also make digital simulation of knitted textiles more challenging. We explore the extent to which available tools can assist during the design process. Firstly, the theoretical aspects of the form-finding of tensile structural systems are discussed. Secondly, the form-finding and analysis of knitted textile structures are explored using Kangaroo2 along with K2 Engineering and Kiwi!3D. The performance of these tools is judged by comparing the digital form-found model against the actual physical model behavior and shape. Results shows that Kangaroo2 is a faster tool than Kiwi!3D when the actual stitch distribution is applied to generate the initial shape; additionally, tuning the length of the mesh edges to replicate the physical model behavior is easier in Kangaroo2. On the other hand, Kiwi!3D is a faster tool if a rough initial simulation for gaining insights into overall form. While Kangaroo2 yields a more detailed and accurate form-found shape, for the FE structural analysis it needs to be coupled with K2 Engineering, or the output of the form-finding from Kangaroo2 can be used as an input for FE analyses using Kiwi!3D. Rather than competing with each other, these software environments are different problem solving approaches; the process requires alternating between these plugins to achieve the project goal. The research shows that in using materials such as knitted textiles to develop architectural forms, successful digital modeling can be obtained by form-finding through the material instead of form-finding onto the material.