From the perspective of the stress principle of bolts. Displayed according to query Mingxin Machinery Network.
1. The principle of bolt anti-loosening method is based on the stress principle of bolts. Bolts are divided into four types: the first is ordinary bolts, high-strength bolts that can withstand vibration loads in towering structures. Ordinary bolts, high-strength bolts, and high-strength bolts that bear alternating tension and compression loads. Ordinary bolts generally bear tension or shear force and are used for the connection of non-important structural components. In the past, it was thought that bolts only need to be tightened during construction. However, the construction quality acceptance regulations for power systems and tower mast steel structure projects have given relatively accurate torque value requirements for torque tightening.
2. The second type of bolt is often used to bear tensile force on tower flanges in tall structures, and the structure can withstand certain vibrations.
3. The force of the third type of high-strength bolt is to first apply pre-tension force to it, and then generate friction resistance on the contact surface between the connected parts to bear the shear force or reduce its pre-tension force to bear the shear force. pull. Generally used in important industrial and civil buildings such as bridge components, this kind of bolts are generally constructed using the torque method. The bolts rely on the friction generated by the compression between threads to prevent loosening. High-strength ordinary bolts are used. The bolts do not apply pre-tension force, but they need to be tightened, and double nuts are used to prevent loosening.
4. The fourth type of bolt is a bolt that withstands alternating tension and compression. This type of bolt generally bears fatigue load at the same time, requires an increase in pre-tension force, and has high anti-loosening requirements. It is common in wind power towers. The connecting flange of the barrel.