Development status and technical characteristics of steel structure for large span space buildings

Non-destructive testing in the process of application will not cause damage to the components, and can obtain accurate results. In the process of applying nondestructive testing, it can visually reflect the properties of the surface, interior and individual specimens of the components. With the development of large span space building steel structure, nondestructive testing technology is widely used. In the process of detection, it is necessary to adopt the correct detection method according to the basic nature of the steel structure, and effectively control the quality of detection.

1.Development status and technical characteristics of steel structure for large span space buildings

1.1 Status of development

Since the 21st century, under the strong support of the state and market demand, China’s steel structure has gained rapid development, leaping to become the “sunrise industry” in the field of construction, and a wide variety of steel structures have appeared in the market, of which the large span space building steel structure is one of the most representative ones. However, in the process of development, there is a shortage of relevant technical personnel, and the quality of the project cannot be controlled, which leads to frequent quality problems in steel structure projects, increases the probability of safety accidents, and causes damage to the personal safety of construction personnel.

1.2 Technical characteristics

Firstly, the steel grade is higher. The construction project has gained unprecedented development, and the construction standard has been optimised continuously, and the steel structure of 100m has been fully applied in the construction at the present stage. China’s Overrun Audit Committee has made clear regulations on the audit of steel structure of large span space buildings, and high-grade materials should be used in the construction to ensure that they meet the strength indexes of the construction. Secondly, the structure is rich in styles. The steel structure of long span space building has diversified styles, and is gradually developing into the mode of arrangement and combination. For example, the Water Cube adopts multi-faceted steel structure, Guangzhou International Convention and Exhibition Centre adopts tensor truss structure, and Beijing Bird’s Nest adopts space truss structure. At the same time, the steel structure incorporates the concept of bionic, so that the nodes of large span space building steel structure are more colourful, such as cast steel nodes. Thirdly, the construction is difficult and demanding. The cross-section of steel structure presents diversified characteristics, with rich variety and different features. In the process of large-scale engineering construction, which contains tens of thousands of steel components, and the length and size of each component is different, and experimental work is also required in the application of moment components. Because the mode of operation is more cumbersome, so it invariably increases the difficulty of construction and increases the risk of quality hazards.

2 Overview and importance of non-destructive testing methods

2.1 Overview of developments

Non-destructive testing (NDT) technology mainly refers to the detection of the surface and interior of the specimen on the basis of damage to the specimen, with the help of physical or chemical methods, and advanced scientific equipment. NDT technology mainly explores unknown defects and can effectively supplement destructive testing. Most of the inspection techniques for steel structures of large-span space buildings were introduced from abroad, and the initial inspection work was to inspect the building of Shenzhen Development Centre. At that time, the application of ray technology for detection work, with the help of ultrasonic detection of welding whether there is a fine seam. With the promotion of steel structure, the inspection technology is more and more abundant. However, the non-destructive testing technology of steel structure for large span space buildings still has certain omissions, which should be optimised in combination with the actual situation.

2.2 Importance

The safety and reliability of a steel structure is closely linked to its design, while its quality is directly linked to its raw materials, processing patterns and fabrication. The use of non-destructive testing (NDT) techniques allows for 100 per cent inspection of workpieces and raw materials at a low cost.