Studies on the influence factors of wind dynamic responses on hyperbolic cooling tower shells

Abstract

Wind induced dynamic responses on hyperbolic cooling tower (HCT) shells are complicated functions of structure and wind properties, such as the fundamental frequency fmin, 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 SigmaB and SigmaR, and their contributions to the total rms value SigmaT. The SigmaR is always less than SigmaB when only the maximum SigmaT along latitude is concerned and the contribution of SigmaR to SigmaT varies with responses and locations, but the SigmaR 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 SigmaR 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.