Membrane structure, as a new form of architecture, breaks the traditional linear architectural style of concrete and steel structures. It often appears in the form of umbrellas, mushroom arrays, spheres, cones, and complex multi curved mixtures, forming various artistic architectural forms. In recent years, the construction quantity of membrane structure buildings in China has developed rapidly, and a large number of landmark membrane structure buildings have emerged, such as the National Sports Center "Bird's Nest", the National Aquatics Center "Water Cube", Tianjin Yujiabao Railway Station, and the Beijing World Horticultural Exhibition "Guirui Theater" and other famous membrane structure projects.



In various membrane structures, membrane structures often appear simultaneously with other building forms to form a complete building unit. Due to the complex shape of the membrane structure, the edge closing components are usually complex spatial structures, making component processing difficult. In addition, the processing dimensions of the edge closing components need to fully consider the construction errors of the membrane structure, and eliminate some construction errors to ensure that the edge closing components of the membrane structure perfectly fit the membrane surface and adjacent decorative components [1,2].



This paper takes the large curvature negative Gauss ETFE cable membrane structure of Suizhou South Railway Station as the research object, uses 3D scanning technology to carry out high-precision reverse modeling of the completed cable membrane structure, and combines Rhino3D and other professional 3D design software to achieve high-precision blanking and processing of complex shape edge closing aluminum plates, ensuring the perfect fit of edge closing aluminum plates with curved facial mask surfaces and adjacent decorative components.



1 Project Overview

The architectural design of the Suizhou South Station building takes the meaning of "Millennium Ginkgo and Ten Mile Gallery". The roof is a steel beam and steel truss structure, designed as an "umbrella shaped unit", supported by 24 reinforced concrete columns. The roof consists of 24 umbrella shaped unit structures, and the bottom of the umbrella shaped unit is a single layer golden ETFE membrane structure (Figure 1).



Figure 1 Umbrella shaped Unit Cable Membrane Structure of Suizhou South Station

Figure 1 Original download of the umbrella shaped unit cable membrane structure at Suizhou South Station





1.1 Overview of membrane structure

The Suizhou South Station building adopts the "umbrella shaped unit" high curvature negative Gaussian single-layer ETFE membrane structure scheme, presenting the artistic shape of ginkgo leaves through the golden ETFE cable membrane structure system. Each umbrella unit is composed of 6 different shaped membranes. The membrane is backed by a 12mm steel cable, forming a synergistic force system with the membrane surface. The edge of the membrane is equipped with an aluminum alloy fixture to form a tension hard edge of the membrane surface. The umbrella shaped unit steel structure is equipped with a tension support for the cable membrane structure, which serves as a fixed support for the steel cable and tension hard edge. The cable membrane structure forms a funnel shape with a large upper and a small lower shape by combining the tension of the hard edges around the membrane surface with the tension of the cable mesh. The surface of ETFE membrane material is a smooth double curved surface with large curvature. The shape and texture of the membrane material and cable net are similar to that of the ginkgo leaf with its petiole downward and its veins vertically extending upward. The shape is flexible and beautiful. At the same time, a 75% transparent golden film material is used in the selection of film materials, and the rough outline of the steel structural members can be seen through the film surface, reflecting the mechanical beauty of the structure (Figure 2).



Figure 2: Plane of membrane structure unit body

Figure 2 Original download image of membrane structure unit plane





Figure 3 Umbrella shaped unit of membrane structure before installation of edge pieces

Figure 3 Original download image of the umbrella shaped unit of the membrane structure before the installation of the edge piece





1.2 Overview of cable membrane structure edge trims