New Progress of High Strength Bolt Connection Technology for Steel Structure

In modern steel structure buildings, high-strength bolt connection plays a crucial role. In recent years, the technology has made remarkable new progress.

In terms of materials, new high-strength bolt materials are constantly emerging. Traditional high-strength bolts are mostly made of high-strength alloy steel, and nowadays, some materials with higher strength, better toughness and corrosion resistance have been developed and applied. For example, some added special alloy elements of steel, its yield strength and tensile strength increased significantly, can withstand greater loads, so that the steel structure is more stable and reliable connection. This is of great significance for large-span, ultra-high-rise and other steel structure buildings that require extremely high structural performance.

In terms of design concepts, the change from purely considering the bearing capacity of bolts to comprehensively considering the overall performance of the structure. The design not only pays attention to the basic mechanical properties of bolts such as tension and shear, but also pays attention to the synergistic working performance of bolts and connection nodes. Through finite element analysis and other advanced means, accurately simulate the stress distribution and deformation characteristics of the bolt connection under different loading conditions, and optimize the arrangement form, quantity and preload size of the bolts to achieve the overall stiffness, stability and seismic performance of the structure. For example, in the seismic design, the reasonable design of high-strength bolt connection can effectively control the energy dissipation and deformation mode of the structure under the action of earthquake, and reduce the risk of structural damage.

In terms of installation process, automated installation technology is gradually emerging. Traditional high-strength bolt installation relies on manual operation, which is difficult to ensure the consistency of installation accuracy and preload. Nowadays, automated tightening equipment is widely used, which can accurately tighten bolts according to preset torque or axial force values, greatly improving installation efficiency and quality. At the same time, some intelligent monitoring systems have also been introduced, real-time monitoring of the installation process of the bolt preload, tightening angle and other parameters, once the deviation can be timely warning and adjustment to ensure that each bolt can meet the design requirements.

In addition, more in-depth research on the durability of the bolt connection. In the process of long-term use, high-strength bolts may face fatigue, relaxation and environmental corrosion and other problems. New research through the improvement of the bolt surface treatment process, such as the use of new anti-corrosion coating, plating technology, to enhance the corrosion resistance of the bolt. At the same time, a large number of experimental studies on the fatigue performance of bolts under repeated loading are carried out to establish a more accurate fatigue life prediction model, which provides a scientific basis for the maintenance and overhaul of steel structures.

In the field of inspection technology, non-destructive testing technology is constantly innovated. In addition to the traditional ultrasonic testing, magnetic particle testing and other methods, some emerging detection technologies such as laser scattering interference technology, electromagnetic ultrasonic detection technology and so on began to be applied to high-strength bolted joints detection. These technologies can more accurately detect the internal defects of bolts, the size of the preload and the tightness of the connection, and there is no damage to the structure, which provides a more powerful means for the quality assessment and safety monitoring of steel structures.

In conclusion, the new progress of high-strength bolted connection technology for steel structure in terms of material, design, installation, durability and inspection will further promote the development of steel structure construction, so that it can play a greater advantage in the field of construction to meet the increasingly complex and diversified building needs.