Dutchy2
Structural
- Jan 10, 2011
- 1
thread507-271837
I found this forum only a couple of days ago, so that's the reason that my reaction is so late.
I don't understand how hoots711 comes to a wall thickness of 20 mm or more for a stack with a height of 40 m and a diameter of 1,2 m.
When I calculate according to ASME-STS1, chapter 4.4 a wall thickness of 8 mm for the bottom part seems more than sufficient (no corrosion allowance, 3 s Gust 50 m/s).
The allowable logitudinal stress is approximately 56 N/mm² (8,1 ksi) and the allowable combination longitudinal + bending stress is approximately 143 N/mm² (20,8 ksi),both with F.S=1,5
The influence of the vortex shedding is reduced by a vibration damper.
Since I am used to European Codes (DIN, Eurocode and also CICIND) it might be possible, that I don't read the ASME-STS1 code correctly, but the 8 mm solution does fully comply with the results of the above mentioned codes.
I found this forum only a couple of days ago, so that's the reason that my reaction is so late.
I don't understand how hoots711 comes to a wall thickness of 20 mm or more for a stack with a height of 40 m and a diameter of 1,2 m.
When I calculate according to ASME-STS1, chapter 4.4 a wall thickness of 8 mm for the bottom part seems more than sufficient (no corrosion allowance, 3 s Gust 50 m/s).
The allowable logitudinal stress is approximately 56 N/mm² (8,1 ksi) and the allowable combination longitudinal + bending stress is approximately 143 N/mm² (20,8 ksi),both with F.S=1,5
The influence of the vortex shedding is reduced by a vibration damper.
Since I am used to European Codes (DIN, Eurocode and also CICIND) it might be possible, that I don't read the ASME-STS1 code correctly, but the 8 mm solution does fully comply with the results of the above mentioned codes.