I am calculating the period of a straight steel stack. Short fat and heavy, my gut says “rigid” for the wind load definitions, but I thought I would check just to make sure. Equation 5.17 on page 5-6 of “Tubular Steel Structures” from Lincoln Welding there is an equation: T=765E-6 x (H/D)^2 x [(12 x w x D)/t]^.5 . I also have a copy of “Pressure Vessel Handbook” which has a formula T=.0000256 x (H/D)^2 x (w x D /t)^.5 . It appears that the Lincoln formula should be ”7.65E-6 x …..” not “765E-6….” Or the Pressure Vessel Handbook is off. That is a difference of 100. At this point I tend to lean towards the Pressure Vessel Handbook formula due to other formulas in the Lincoln book. But I could be wrong.
Can anyone out there confirm this?
Thanks,
Joe
Joseph R. Grill, PE