Studies on the Influence Factors of Wind Dynamic Responses on Hyperbolic Cooling Tower Shells

Wind induced dynamic responses on hyperbolic cooling tower (HCT) shells are complicated functions of structure and wind properties, such as the fundamental frequency f(min), damping ratio zeta, wind velocity V, correlationship in meridian direction and so on, but comprehensions on the sensitivities of the dynamic responses to these four factors are still limited and disagree from each other. Following the dynamic calculation in time domain, features of dynamic effects were elaborated, focusing on the background and resonant components sigma(B) and sigma(R), and their contributions to the total rms value sigma(T). The sigma(R) is always less than sigma(B) when only the maximum sigma(T) along latitude is concerned and the contribution of sigma(R) to sigma(T) varies with responses and locations, but the sigma(R) couldn't be neglected for structural design. Then, parameters of the above four factors were artificially adjusted respectively and their influences on the gust responses were illustrated. The relationships of sigma(R) and the former three factors were expressed by fitted equations which shows certain differences from the existing equations. Moreover, a new strategy for wind tunnel tests aiming at surface pressures and the following dynamic calculations, which demands less experiment equipment, was proposed according to the influence from meridian correlationship.