【摘要】 冷却塔在随机风荷载激励作用下,动力响应具有小变形、弱非线性特点,固有频率在低频段密集分布,模态之间耦合效应较为明显。基于冷却塔刚体模型表面同步测压风洞试验结果,以非定常气动力作为输入荷载,考虑冷却塔多模态之间耦合效应,利用虚拟激励法和振型迭加法进行结构随机风振响应分析。定量地比较了结构风振响应中背景分量和共振分量的贡献,研究了参振模态数目、力谱交叉项和结构阻尼比等参数的作用效果,并与冷却塔气弹模型测振风洞试验结果进行了比较。更多还原

【Abstract】 Under action of stochastic wind loading, dynamic responses of a cooling tower show small deformation and weakly nonlinear characteristics. Its natural frequencies centralize in a lower frequency band, coupling effects between various modes are obvious. With help of syrface aerodynamic pressure of a 1∶200 reduced-scale cooling tower model which was measured in TJ-3 wind tunnel, the stochastic response of a full-scale cooling tower was calculated using pseudo-excitation method and superposition method, considering the coupling effects between modes. The contributions of background components and resonant ones were quantified and the effects of different parameters, such as, modal numbers, cross terms of force spectra, damping ratio etc, were systematically studied. The numerical calculation results were in good agreement with the dynamic responses measured on the 1∶200 reduced-scale cooling tower aeroelastic model.更多还原