说明：  自然激励下建筑结构的模态参数识别，首先通过自然激励技术（next）得到结构的自由响应，然后由自回归滑动平均（arma）方法识别模态参数。
(natural incentive structures under the modal parameter identification, First through natural incentive Technology (next) to be free to respond to the structure, then autoregressive moving average (arma) identified modal parameters.)