Department of System Design Engineering, Keio University, Yokohama 223-8522, Japan.
Sensors (Basel). 2021 May 23;21(11):3629. doi: 10.3390/s21113629.
Only one accelerometer is used in this paper for estimating the maximum inter-story drifts and time histories of the relative displacements of all stories of multi-degree-of-freedom (MDOF) shear structures under seismic excitation. The calculation based on the data of one sensor using a conventional method is unstable, and when modal coordinates are used, higher modes should be included, which is different from the estimation based on the responses recorded by many accelerometers. However, the parameters of the higher modes of structures are difficult to obtain from structures under small excitations. To overcome this difficulty, the recorded absolute acceleration is converted into the absolute displacement, and a state-space equation is formulated. Numerical simulations of a nine-story structure were conducted to check the applicability, robustness against environmental noise, and optimal installation location of the accelerometer of the proposed approach. In addition, the effects of the higher modes were analyzed in terms of the number of accelerometers and type of response. Finally, the proposed approach was validated in a simple experiment. The results indicate that it can accurately estimate the time histories of the relative displacements and maximum inter-story drifts of all floors when one accelerometer is used and just the first two modal parameters are incorporated in the model. Furthermore, the approach is robust against environmental noise.
本文仅使用一个加速度计来估计多自由度（MDOF）剪切结构在地震激励下的最大层间位移和所有楼层相对位移的时程。基于一个传感器数据使用传统方法进行计算是不稳定的，而当使用模态坐标时，应该包括更高阶模态，这与基于多个加速度计记录的响应的估计不同。然而，从小激励下的结构中很难获得结构的高阶模态参数。为了克服这个困难，将记录的绝对加速度转换为绝对位移，并建立状态空间方程。对一个九层结构进行了数值模拟，以检查所提出方法的适用性、对环境噪声的鲁棒性和加速度计的最佳安装位置。此外，还分析了高阶模态对加速度计数量和响应类型的影响。最后，在一个简单的实验中验证了该方法。结果表明，当仅使用一个加速度计且模型中仅包含前两个模态参数时，该方法可以准确估计所有楼层的相对位移和最大层间位移的时程。此外，该方法对环境噪声具有鲁棒性。
