为获取桥梁断面涡激共振过程中的气动效应特性,提出一种基于风洞试验的气动效应特性识别方法,首先提出涡振系统总体阻尼及刚度瞬时特性识别方法,在此基础上提出从涡振系统总体阻尼及刚度中分离气动阻尼及气动刚度的方法.以一个开口断面风洞试验数据为例对该方法的准确性进行了验证,并对该断面涡振气动效应特性进行研究.结果表明:识别得到的系统总体阻尼比为零的等高线与结构涡振响应曲线能很好吻合,从而验证了该方法的准确性.在此基础上对涡振过程中作用于结构的气动阻尼及气动刚度特性进行了研究,获得了气动阻尼及刚度随结构振幅和约化风速的变化规律,可为后续理论模型研究提供参考.
To identify the aeroelastic effects on bridge decks during vortex-induced vibration (VIV), a new method is proposed. The procedure of instantaneous identification of the VIV system is firstly proposed. Based on this procedure, the method for extracting the aeroelastic damping and stiffness from the total damping and stiffness of the VIV system is establised. Data of wind tunnel experiments on an open-section bridge deck undergoing vortex- induced resonance is involved for validation and for studying the features of aeroelastic effects on this deck during VIV. The zero-contour of the total damping for the VIV system compares well with the experimental VIV responses, which confirms the accuracy of this method. Based on the resuhs, aeroelastic effects at different wind velocities and amplitudes on this open-section bridge deck are studied in detail, which can offer some valuable information for the subsequent study on mathematical modeling of this phenomenon.