摘要
采用系统辨识方法对场地土动力响应进行建模和分析。结合北京某环境影响评价项目,以力锤激励为振动源强,基于场地土振动实测数据计算连续传递函数。分析传递函数阶数对传递函数时域辨识均方误差的影响,基于均方误差最小化准则,确定最优的连续传递函数辨识模型及其数学表达式。基于此辨识模型,进行场地土传递函数增益分析、幅频响应分析和脉冲响应分析。结果表明:随着阶数增加,连续传递函数模型的均方误差呈现先减小后增大的趋势;阶数大于15时连续传递函数模型的均方误差显著增加,实测加速度与根据模型计算所得的加速度之间偏差变大;与激励点距离较近的测点传递函数增益较大,振动以高频为主且衰减较快;与激励点距离较远的测点传递函数增益较小,振动以低频为主且衰减较慢。
System identification method is used to model the dynamic response of site-soil.With the hammer excitation as a vibration source,the continuous transfer function of the system is calculated based on the measurement data of a site soil vibration test.The influence of the order of the transfer function on the mean square error of the identifying model is analyzed.The optimal identifying model is determined by minimizing the mean square error of the model.Based on the identifying model of the site soil,transfer function gain analysis and impulse response analysis are carried out.The results show that with the order increasing,the mean square error of the identifying model initially decreases and then increases;the difference between the tested acceleration and the calculated acceleration of the model increases.When the order is greater than 15,the mean square error of the identifying model increases significantly.The responses at the points near the excitation point are dominated by high-frequency vibration and decay rapidly,while the responses at the points far away from the excitation point is dominated by low frequency vibration and decay slowly.
作者
曾宇
邬玉斌
宋瑞祥
吴瑞
ZENG Yu;WU Yubin;SONG Ruixiang;WU Rui(Beijing Municipal Institute of Labour Protection,Beijing 100054,China)
出处
《噪声与振动控制》
CSCD
2018年第4期140-143,191,共5页
Noise and Vibration Control
基金
北京市财政资助项目(PXM2016_178304_000011)
关键词
振动与波
场地土
动力响应
系统辨识
传递函数
vibration and wave
site soil
dynamic response
system identification
transfer function
