The ends of the micro crack are expanded, and a macro plastic storage tank is formed, which is caused by the fatigue crack. The failure of the pressure vessel under the action of cyclic alternating stress is called fatigue.
Fatigue failure is the failure of the formation and development of cracks.
When fatigue failure occurs, there is no obvious plastic deformation, which always occurs in the local high stress area.
Plastic failure criterion is the shell stress limit in the plastic range, according to the plastic yield condition, the shell bearing limit in the plastic state, thought the shell all the yield is the biggest limit for shell.
The failure criterion of blasting is that the shell material is made of ductile material, the steel has obvious change phenomenon, and it is the biggest limit of bearing capacity after the shell's total yield.
The basic principle of the sealed plastic storage tank is: the media through the sealing mouth of the pressure difference between two sides of the seal, the media is sealed;
On the contrary, the media will leak.
The medium through the sealing surface resistance is achieved by the pressure on the sealing surface to achieve the role in the sealing surface of the seal than the greater pressure, the media through the sealing of the resistance is also greater, the more conducive to sealing.