Membrane structure sunshade Inflatable membrane structure relies on continuous indoor inflation to generate a certain pressure difference between indoor and outdoor (generally between 10 mm~30 mm water column). The pressure difference between indoor and outdoor makes the roof membrane cloth subject to a certain upward buoyancy, so as to achieve a large span. The tensioned membrane structure is supported by columns and steel frames or tensioned by steel cables. The design of membrane structure mainly includes body shape design, initial balance shape analysis, load analysis, and cutting analysis. Determine the plane shape, size, 3D shape and clearance volume of the building through figure design, determine the coordinates and structural form of each control point, and select membrane materials and construction scheme. Initial equilibrium shape analysis is called form finding analysis. Since the membrane material itself has no compression and bending stiffness, and the main shear strength is very poor, its stiffness and stability need to be improved by the curvature change of the membrane surface and the prestress in it. For the membrane structure, there is no stress free state at any time, so the shape of the membrane surface must finally meet the mechanical balance under certain boundary conditions and certain prestress conditions, Based on this, load analysis and clipping analysis are carried out. The main form finding methods of membrane structures include dynamic relaxation method, force density method and finite element method.
At present, the development of membrane structures in China is inspiring. With the construction of some large stadiums and waiting halls, as well as the holding of international events such as the 2010 Shanghai World Expo and the Guangzhou Asian Games, the development of membrane structures in China has brought opportunities and challenges. Especially in the field of membrane materials, China started late and its technology level is low. Most membrane materials still rely on imports. PTFE, PVC, surface modified PVC, ETFE and other membrane materials are the mainstream of the market and are widely used. China has its own intellectual property rights of PTFE membrane materials, and its performance basically meets the requirements of similar foreign products. Many companies, scientific research institutions and universities are carrying out research on PVC surface coating materials, such as PVDF, nano TiO2 surface coating agent, etc., which has achieved initial results. In addition, research on surface anti fouling and self-cleaning treatment, such as bionic lotus leaf construction of micro rough surface, is also starting. While introducing world-class production equipment and process technology, it is of great significance to accelerate digestion, absorption, improvement and innovation, and develop membrane surface treatment technology suitable for the needs of the Chinese market as soon as possible to improve the grade and market competitiveness of China's entire industrial textile products.
Membrane structure is a kind of spatial structure form that uses a variety of high-strength membrane materials (PVC or Teflon) and stiffeners (steel frame, steel column or steel cable) to generate a certain amount of pretension stress in its interior through a certain way to form a certain spatial shape, as a covering structure, and can withstand a certain amount of external load. Membrane structures can be divided into inflatable membrane structures and tensioned membrane structures. Inflatable membrane structure relies on continuous indoor inflation to generate a certain pressure difference between indoor and outdoor (generally between 10 mm~30 mm water column). The pressure difference between indoor and outdoor makes the roof membrane cloth subject to a certain upward buoyancy, so as to achieve a large span. The tensioned membrane structure is supported by columns and steel frames or tensioned by steel cables.
