Design solutions for the barrel vault FreeGrid Design Baseline Gridshell

This paper presents a contribution in the framework of FreeGrid, a benchmark on design and optimization of free-edge steel gridshells. The present study focuses on the barrel vault gridshell and proposes three Design Solution Gridshells (DSG), whose performances are evaluated with respect to the Design Baseline Gridshell (DBG). The proposed DSGs share the same geometry, mesh pattern, type of crosssection and material of the DBG. Enhancement of the performances is obtained through a design-fromprecedent approach, i.e. taking inspiration from previous design solutions. In particular: the free-edge flexural stiffness is increased by simply changing its cross-section; the free-edge is stiffened through a truss-girder laying on the vault surface, in analogy e.g. with Nervi’s hangars; an unprecedented solution for gridshells is borrowed by masonry barrel vaults, ased on the deviation of thrusts from free-edge to lateral constraints by means of a relieving arch laying on the vault surface. The structural performances of DSGs are valuated through the metrics adopted in the FreeGrid benchmark. Comparison with the DBG structural metrics allows to discuss pros and cons of each solution and to rank them.