Valve Industry Development And Intelligent Manufacturing Trend Analysis
Cast Ball Valve Industry Development and Intelligent Manufacturing Trend Analysis
In recent years, with the support of modern technology and the addition of new materials, large-span space steel structures such as grids, lattice shells, and tube truss structures have been widely used. However, to ensure the healthy development of large-span space steel structures, it is also necessary to accelerate the formulation of a series of space structure industry standards, strengthen the qualification certification and management of steel structure enterprises, and improve the design, production, and installation level of large-span space steel structures.
Since the grid began to be used in my country in the 1960s, large, medium, and small span grids have been almost everywhere in the 1980s and 1990s. Taking the 1990 Beijing Asian Games as an example, 7 of the venues built adopted grid and lattice shell structures. During this period, many large-scale industrial plants were built in the machinery, automobile, chemical, light industry and other industries, and a large number of large-span space steel structures in various forms were also adopted. Most of the large public buildings built in recent years have adopted tube truss structures with direct intersection of steel pipe rods. They have rich appearance, light structure, simple force transmission, convenient production and installation, and good economic effect. They are a kind of structural system that is currently used more.
According to experts, the introduction of modern prestressed technology in large-span spatial structures not only enriches the structural shape but also fully demonstrates its advancement, rationality and economy. By properly configuring the cables, the structure can obtain a new intermediate elastic support or generate internal forces and deflections in the opposite direction of the external load to unload. The former is a cable-stayed structure system, and the latter is a prestressed structure system. This type of "hybrid" structural system improves the stress state of the original structure, reduces the peak value of the internal force, enhances the structural rigidity, and significantly improves the technical and economic effects. At present, my country has applied prestressed technology in more than 80 large-span spatial steel structure projects.
