19 17 an American named Lanchester suggested blowing up the membrane cloth with a newly invented electric blower to make it a field hospital. Like many patent applications, this is just an idea and has not really become a usable product.
1946, a man named Walter Baird made a circular inflatable radome with a diameter of 15m for the US military, which can protect the radar from the weather and let the radio waves pass unimpeded, thus putting this patent with an interval of 19 years into practice. A new industry has been derived from this. After 1956, more than 50 membrane structure companies were established in the United States to manufacture various membrane structure products, which were used as sports facilities, exhibition venues, equipment warehouses, light industrial plants and so on. However, many unfortunate incidents were caused by poor design, rough production or improper maintenance by owners, and most factories closed down.
During the period of 1960, Mr Frey Otto of the University of Stuttgart, Germany published the research results of membrane structure in 1962 and 1965 respectively, and made some tent membrane structures and cable structures in cooperation with tent manufacturers, the most striking of which was the West Germany Pavilion of the 1967 Montreal World Expo, which was in Europe. Especially from 65438 to 0968, the architect Brody from new york and Professor David Geiger from Colombia jointly won the right to design the American Pavilion of the Osaka World Expo. The initial fund of $25 million has been reduced to $2.5 million again and again, and the design team has taken on great challenges. Under the condition that poverty will change and change will lead to communication, a large pit will be dug in the base, waste soil will be piled around it, concrete pressure ring will be poured on it, steel wire mesh will be fixed on the ring, then film cloth will be fixed on the steel wire mesh, and then it will be inflated, thus making a 9290㎡ exhibition hall. Between 1968 and 1987, there are eight indoor gymnasiums designed and built in this way.
At the Osaka World Expo, Geiger successfully introduced the new design technology of air-bearing membrane structure to the world, but after being unanimously recognized by the construction engineering community, it was faced with the problem of membrane materials used. The life of this membrane material is only 7-8 years. Under the interaction of solar ultraviolet rays and wind and rain, membrane cloth will become hard, brittle and broken, and lose its structural performance. Only by using good membrane cloth materials can this long-span roof become a permanent building. At this time, the educational facilities laboratory under the Ford Foundation of the United States gave Geiger a sum of money to develop this permanent building membrane. Under the leadership of Geiger Company, together with DuPont Company, Corning Glass Fiber Company, Baird Construction Company and Chemical Fiber Weaving Company, the permanent structural membrane was developed. The product was successfully manufactured. The chemical fiber company first integrates the glass fiber provided by Corning Company, and then weaves it into cloth yarn. After soaking in silicone rubber, it was first made into a water-tight grey cloth, and then quickly put into PTFE solution for many times, so that both sides of the grey cloth were evenly coated with PTFE, and a permanent PTFE film was formally born. After accelerating the climate experiment, its physical stability was determined. Geiger Company designed various structural fittings and determined the design procedures for building membrane structures with different properties. John Seaver, an architect in Kansas City, pioneered this product and built a student activity center in La Fern, California. In addition, Jiping also built an air-bearing swimming pool (raised roof) and a student activity center at 1973 California Santa Crolla. Since then, the permanent membrane structure has officially become popular in the United States.
1. Regarding the structural membrane, the general steel roof is a roof panel supported by a bridge, which is covered with a waterproof and thermal insulation layer. These roof materials are not affected by structural forces. The membrane itself in the membrane structure bears live loads including wind pressure and temperature stress, and the membrane is both a cover and a part of the structure. According to the classification of materials, there are two kinds of structural films: 1) plane nonwoven films: films extruded from various plastics in the state of heating and liquefaction, with different thickness, transparency and color, and polyethylene films are the most common. There is also a composite film made of polyethylene and polyvinyl chloride after hot melting, which has strong ultraviolet resistance and self-cleaning, and its service life can be extended from 7 years to 15 years. This kind of membrane belongs to semi-structural membrane material because of its low tensile strength and small span. 2) Woven synthetic film: the market center is woven with polyester yarn, coated with PVC resin on both sides, and then covered with a layer of polyvinyl fluoride film by hot melting to make a composite film, and the service life is extended from 7 years to 15 years. Because of its high tensile strength, the cloth core can be used in various tension structures with a span of 8m- 10m. Many brands are produced in the United States, Japan, France and other countries. 2. Several membrane structures combined with the above structural membranes can be classified into the following categories: 1) The pure steel arch structure adopts the traditional beam-column system, the roof is a circular arch, and the spacing between columns and beams is generally about 8m. 2) The two simplest membrane structures, concrete structure main body and steel arch, can be changed according to the plane shape, such as square and diamond, and the arch spacing is determined according to the strength of the membrane material used, design load and wind force. 3) The main structure of concrete and the ridge of steel cable bend upward, located under the membrane cloth, and the valley cable bends downward, located on the membrane. After the two kinds of steel cables are bent in opposite directions, vertical forces in opposite directions are caused, which makes the film market subject to vertical tension, and the horizontal tension in the film cloth is formed by direct tension. 4) Concrete main structure with steel columns 5) Tension tent membrane structure 6) Large (over 200m in span) air-bearing membrane structure can be made into large-span giant roof with flat steel cables and membrane cloth. This kind of building has the advantages of simple structure, convenient construction, high economic benefit and maintenance-free. However, due to the need to keep it closed all the year round, it is inconvenient to get in and out, so it is no longer built, but it is still a good structural form. Because the membrane structure needs precise design and tailoring to achieve the ideal effect, David and Geiger, together with colleagues Mike, Mark Mike and Joseph Wright of Columbia University, developed a nonlinear cable calculation program, which laid the foundation for the engineering design of large-scale membrane roofs supported in the air. From 1973 to 1978, 12 large indoor air-supported membrane gymnasiums have been built all over the world. Compared with other gymnasiums built at the same time, these membrane structure gymnasiums are not only low in cost, but also fast in construction.