Cause and analysis of high temperature and high strength bolt fracture
Threaded fasteners loose not because bolt fatigue strength: 1 threaded fasteners in transverse vibration experiments can loose with one hundred times, and in the fatigue strength test should be repeated oscillation one million times. Threaded fasteners, in other words, the loose when applying the fatigue strength of one over ten thousand, let's use only one over ten thousand of its large capacity, a threaded fasteners loose so not because the bolt fatigue strength. 1 damage was the real reason for loose thread fasteners: 1 loose thread fasteners, produce infinite mv2 kinetic energy, the boundless momentum directly acting on the fasteners and the equipment, the damage of fasteners, fastener damage, under the conditions of normal equipment did not work, further cause equipment damage.
The fastener which is affected by the axial force, the thread is damaged and the bolt is broken.
The bolt is cut and the bolt hole is broken into an ellipse.
The best way to prevent loose threads is to solve the problem
At present, the most advanced and effective anti-loose method is the anti-loose method of the tang's thread fastener.
Threads have the characteristics of left and right threads. It can work with both left and right threads. Use two different rotating nuts when connected. The nut on the operating support surface is called a fastening nut, and the nut on the non-supported surface is called a locking nut. Tighten the nut before using, and then tighten the lock nut.
Under the condition of the vibration, impact, fastening nut loose trend will attack, but, because of the fastening nut loose retreat direction is tighten the lock nut, lock nut tighten precisely to prevent the fastening nut loose, loose fastening nut is impossible.