论文部分内容阅读
为研究Rayleigh阻尼系数参考频率选取方法对结构地震反应的影响,以一个长85.2 m,宽61.8 m的网壳为例,对比分析了基于地震波频谱特性选取第二个参考频率的方法、Idriss方法、传统方法、优化方法所得Rayleigh阻尼系数引起顶点位移和基底剪力计算误差.对于地震波的频谱特性,讨论了拟加速度反应谱、拟速度反应谱、位移反应谱的峰值频率和形心点频率的统计范围.数值计算结果表明:基于拟速度反应谱、位移反应谱峰值频率和形心频率以及Fourier谱的峰值频率所得Rayleigh阻尼将使计算结果偏小;用小于基本周期范围内的拟加速度反应谱的峰值频率或形心点频率作为第二个参考频率计算误差较小;当地震波的卓越频率大于基频的结构时,Idriss方法用平滑化Fourier谱的卓越频率计算参考频率效果更好;优化方法可以直接得到Rayleigh阻尼系数,避免了人为选取参考频率的任意性,且计算精度高.
In order to study the influence of Rayleigh damping frequency selection method on the seismic response of structures, taking a 85.2 m long and 61.8 m wide latticed shell as an example, the method of selecting a second reference frequency based on the spectral characteristics of seismic waves is compared and analyzed. The Idriss method, The Rayleigh damping coefficients obtained by the traditional method and optimization method cause the calculation errors of the vertex displacement and the base shear force.For the spectral characteristics of seismic waves, the statistics of the peak frequency and centroid frequency of quasi-acceleration response spectrum, quasi-velocity response spectrum and displacement response spectrum are discussed The numerical results show that the Rayleigh damping based on the quasi-velocity response spectrum, the peak frequency and the centroid frequency of the displacement reaction spectrum and the peak frequency of the Fourier spectrum will make the calculation result small, and the quasi-acceleration response spectrum less than the basic period The error of the peak or centroid frequency is less than that of the second reference frequency. When the superior frequency of the seismic wave is greater than that of the fundamental frequency, the Idriss method is more effective in calculating the reference frequency with the superior frequency of the smoothed Fourier spectrum. The optimization method can The Rayleigh damping coefficient is directly obtained, avoiding any artificial selection of the reference frequency Sexual, and calculation accuracy is high.