H.A. Mang:
"Discussion of Paper "Wind-Buckling Approach for RC Cooling Towers" by W. Zerna, I. Mungan, W. Steffen";
Journal of the Engineering Mechanics Division, 110 (1984), 1163 - 1165.
The author's Buckling Stress States (BSS)-Approach for determination of the wall thickness of wind-loaded cooling towers is based on the intuitively appealing idea of initiation of buckling being a local phenomenon. Their truss model yields the same local buckling stress in the two weak members of the symmetrically loaded truss as in the weak member in compression of the asymmetrically loaded truss. Transferring this observation to cooling tower shells, the authors arrive at a rationale for threating wind-buckling of these structures as an axi-symmetric problem.Assuming it was feasible to carry out the author's truss tests, using a material for the truss members with a ratio of compressive to tensile strength similar to the one of concrete, then - depending on the member dimensions - either buckling of the weak member in compression in Fig. 2 or fracture of the weak member in tension would be found to be the relevant mode of failure initiation. Adapting this statement to wind-loaded axisymmetric shells, either local buckling or cracking would initiate the process of loss of stability.