Modular Connector for Resilient Grid-Shell Structures

Abstract

In the design, fabrication, and erection of grid shells, a major challenge is the nodal connector between members. Designers typically select a structure’s form and then design the nodal connectors to meet geometric and structural demands. However, this can lead to complicated connections that are difficult and expensive to fabricate. Each connector is also often unique. To address these challenges, this paper investigates a new approach in which a novel modular connector is designed for ease of fabrication and erection, and then structural forms are developed that use the connector repeatedly to join wide flange steel members via splice connections in double shear. This approach modularizes the nodal connector, which is a prefabricated, steel connector with starter segments that include webs and flanges. The flanges and webs of the modular connector and the members are joined independently, thereby achieving a moment-resisting connection. This facilitates trusslike, membranelike, or beamlike behavior and allows loads to be redistributed in the case of sudden member loss or replacement, thereby providing enhanced resiliency. Variability in form is achieved by bending the flange splice plates. This paper investigates the modular connector for free-form undulating grid shells and for rational structural forms developed through a proposed form-finding methodology. The proposed methodology relies on thrust network analysis coupled with geometric and structural constraints. The promise of the modular connector and the proposed methodology is demonstrated through finite-element numerical analyses.