Thin vs Thick Cylinder Pressure Vessel
Thin vs Thick Cylinder Pressure Vessel
(OP)
I am in the midst of designing a titanium pressure vessel to be deployed at a 6km (8800 psi) depth and needs to have a FOS of 1.25 minimum. The design as it now exists has an ID of 4.375" and a wall thickness of .302" and an unsupported length of 16.7". Most of the critical design equations for buckling of cylinders focus on "thin" cylinder defined as R/t>10, where this design incorporates a ratio of 7.73. I have read most of the available research on buckling of cylinders and how less than predicted pressures buckling occurs, but again these were all thin cylinders and not titanium. My question is can the predictions made on the basis of the thin cylinder analysis and testing be considered conservative for a design which is just outside the strict definition of a thin cylinder?





RE: Thin vs Thick Cylinder Pressure Vessel
RE: Thin vs Thick Cylinder Pressure Vessel
This FOS you state, 1.25, is against which failure mode and which loading condition(s)?
RE: Thin vs Thick Cylinder Pressure Vessel
RE: Thin vs Thick Cylinder Pressure Vessel
Regards,
Mike
RE: Thin vs Thick Cylinder Pressure Vessel
RE: Thin vs Thick Cylinder Pressure Vessel
Whether or not you have the in-house capability to perform such work doesn't relieve you of the necessity to perform such analysis.
RE: Thin vs Thick Cylinder Pressure Vessel
RE: Thin vs Thick Cylinder Pressure Vessel
RE: Thin vs Thick Cylinder Pressure Vessel
RE: Thin vs Thick Cylinder Pressure Vessel
RE: Thin vs Thick Cylinder Pressure Vessel
RE: Thin vs Thick Cylinder Pressure Vessel
Yes, it is quite the condundrum. What are your fabrication tolerances on things like out-of-roundness?
RE: Thin vs Thick Cylinder Pressure Vessel
RE: Thin vs Thick Cylinder Pressure Vessel
ASME PV standards not in the office. No control of critical features. Poor testing protocols.