2idt

代码说明：

  ITD进行模态识别，得到模态参数,ITD 法是一种单输入多输出、基于包含系统参数的自由振动方程识别结构参数的方法，(ITD modal identification, get the modal parameters.ITD method is a single-input multiple-output, based on the structure of the free vibration equation parameters include system identification method parameters,)