Compression Capacity of a Fluted Column 1

[curiousstructural]

I am analyzing the compression capacity of a fluted column which is the central column of an Elevated Water Tank. I have the values of the Column Diameter and the thickness values obtained from ultrasonic tests. The thickness is 0.25" approx. I am designing based on AWWA D100-11. Can the column be designed as a "non-slender" element because of the presence of flutes? If yes, how can I justify it mathematically?

Thanks

 

[BAretired]

"Theory of Elastic Stability" by Timoshenko and Gere discusses the buckling of cylindrical shells under uniform axial compression. The theory is not particularly easy to follow, and Section 11.4 "Experiments with Cylindrical Shells in Axial Compression" contains the following note:

"It is seen that in all cases failure has occurred at a stress much lower than the theory predicts. In not one case was the ultimate stress more than 60% of the theoretical...the discrepancy between experiment and theory is larger for thinner shells."

BA