厦门沿海某超高层建筑结构风致振动动力特性研究

现场实测是获得结构风致振动动力特性参数的一种较为可靠的手段和方法。通过对厦门沿海某超高层建筑在台风登陆时进行现场原型实测，得到了该建筑结构的第10层、18层、23层、28层、33层和36层的加速度响应时程数据和固有频率及振型等结构的动力特性。根据实测加速度数据，利用随机减量法提取结构两方向的前3阶固有频率对应的阻尼比，结果表明：由于实测时台风风速较大，导致结构风致响应较为显著，因此结构两个方向第1阶阻尼比值在7%左右，明显大于另外两阶阻尼比；两方向第1阶阻尼比与加速度呈非线性关系，阻尼比随加速度的增大而增大。采用ANSYS软件建立该超高层建筑的3D有限元分析模型并进行模态分析，提取该模型的前3阶固有频率和振型，与实测结果进行对比分析，结果较为吻合，由此说明所建立的3D有限元分析模型正确可靠。

Study on wind-induced vibration characteristics of coastal high-rise building in Xiamen

The field measurement is a reliable approach to get the dynamic characteristics of a structure. By full-scale measurement, the structural dynamic characteristics of a high-rise building in Xiamen were obtained when typhoon landed, which included the acceleration data of six levels, the natural frequency and the vibration models. Meanwhile, the random decrement method was adopted to extract the damping ratios corresponding to the first three modes of the frequency on the basis of the measured data. It is indicated that, the value of the damping ratios for the first mode in two directions are about 7% due to the significant wind-induced structural response resulted from the large wind speed. Moreover, the damping ratios for the first mode increase nonlinearly with the increase of the acceleration. Furthermore, the finite element 3D model was established by ANSYS to analyze the dynamic characteristics of the studied building, which agreed with the identified results from field measurement very well. Therefore, the finite element 3D model has been confirmed to be reasonable.