Dynamic Characteristics Analysis of a Seismic Vibrator-Ground Coupling System
Dynamic Characteristics Analysis of a Seismic Vibrator-Ground Coupling System
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DOI：
10.1155/2017/2670218
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发表时间：
2017
影响因子：
1.6
通讯作者：
Liu Jun;Zhichao Huang;Li Gang;Li Shide;L. Xian;Zhang Kai
中科院分区：
文献类型：
--
作者：
Liu Jun;Zhichao Huang;Li Gang;Li Shide;L. Xian;Zhang Kai
基于振动器底板结构和土壤特性的动态分析，提出了描述地震振动器和地面耦合的数学模型。该数学模型使用纽马克方法求解。它产生了合理的结果，并且幅度包络的趋势遵循实验数据。利用该模型，可以对振动器-接地耦合进行表征。模态分析研究表明，振动器反作用质量与基板之间的运动经历一阶振动模式和二阶振动模式的组合。两种振动模态对应的频率分别位于2.77 Hz和488.7 Hz。随着频率升高，反应质量和基板的运动行为以二阶振动模式为主。研究发现，二阶振动模式是造成输入扫描信号和输出力信号之间相位差的原因。此外，还研究了耦合系统参数对振动器输出力的影响。可以观察到，随着扫描频率的增加，振动器输出力减小。反作用质量和底板的重量比对振动器输出力有影响。
A mathematical model to describe the seismic vibrator and ground coupling is proposed based on dynamic analyses of the vibrator baseplate structure and properties of soil. This mathematical model is solved using Newmark’s method. It produces reasonable results and the trend of amplitude envelope follows the experimental data. With this model, characterization of the vibrator-ground coupling is performed. Modal analysis study shows that the motions between the vibrator reaction mass and baseplate experience a combination of a first-order vibration mode and a second-order vibration mode. The corresponding frequencies of two vibration modes are located at 2.77 Hz and 488.7 Hz, respectively. As the frequency goes up, the motion behavior of the reaction mass and baseplate is dominated by the second-order vibration mode. It is realized that the second-order vibration mode is responsible for the phase difference between the input sweep signal and the output force signal. Furthermore, the impact of the coupling system parameters on the vibrator output force is also investigated. It is observed that the vibrator output force decreases as the sweep frequency increases. The weight ratio of the reaction mass and the baseplate has an impact on the vibrator output force.