Pioneering Space Truss Constructed from Cold-Formed Steel

Abstract

This article presents pioneering and unprecedented work that has direct applications in improving the structural performance of cold-formed steel (CFS) buildings. The proposed product, space trusses made with cold-formed stamped diagonal, aims to generate safer structures due to rigidity in three directions. The conventional three-dimensional steel trusses are made with hot-rolled steel bars, generally using tubes, connected by bolts at the nodes. Although there are several types of connections to attach these members, most of them are patented and expensive. This study investigates nodes produced by stamping the ends of the CFS members, thus generating a low-cost connection. In this work, a technique for axis eccentricity correction was developed, leading to an original type of node. A formula for calculating eccentricity correction was suggested and applied to cold-formed three-dimensional (3D) trusses. Additionally, the behavior of prototypes was analyzed in finite element models. To prove the efficiency, a prototype with an area of 4.0 m2 (external dimensions of 2×2 m2) was studied. The structure presented excellent results, with a self-weight of 0.825 kN compared with a load capacity of 71.8 kN, meaning it could support 88 times its self-weight. The research concluded that 3D trusses of CFS have great potential in building construction.