Background:
I am involved with water treatment pressure vessels that range from 20" to 168" in diameter. These tanks are vertical and generally supported on (4) angle, beam, or channel legs welded to the cylindrical portion of the shell. They are always 100% filled with water once they go into service.
So here is my question:
When calculating the natural period I see two options:
1. The diameter to shell length ratio is high (short shell), so the vessel acts like a lumped mass on a spring with the legs being the spring.
2. The diameter to shell length ratio is low (tall shell). In this case the lumped mass assumption shouldn't be made.
So, is there any guidance around on when the lump mass assumption should be avoided?
Thanks in advance.
I am involved with water treatment pressure vessels that range from 20" to 168" in diameter. These tanks are vertical and generally supported on (4) angle, beam, or channel legs welded to the cylindrical portion of the shell. They are always 100% filled with water once they go into service.
So here is my question:
When calculating the natural period I see two options:
1. The diameter to shell length ratio is high (short shell), so the vessel acts like a lumped mass on a spring with the legs being the spring.
2. The diameter to shell length ratio is low (tall shell). In this case the lumped mass assumption shouldn't be made.
So, is there any guidance around on when the lump mass assumption should be avoided?
Thanks in advance.
