希尔伯特-黄变换(HHT)是具有适应性的局部化时频分析方法,适用于非线性、非平稳的信号分析。该文基于主动监测技术,将结构健康和损伤状态下的响应信号进行对比,二者的差信号实际上是激励信号通过损伤折射后被接收到的一种信号。利用HHT对差信号和激励信号等进行分析,提取信号群速度的到达时刻,从而得到差信号的传播时间。根据差信号传播路径的分析,并结合四点圆弧定位方法,实现二维结构的损伤定位,实验验证利用HHT信号处理技术能够有效准确的进行复合材料结构的二维损伤定位。
HHT is an adaptive local time-frequency representation and applied to analysize nonlinear and nonstationary data. It is used to locate the two-dimensional damage in the composite material. This paper adopts the active monitor technique and compares the health signal and the damage signal to achieve the differential signal. HHT technology is utilized to analyze the differential signal and the exciting signal to acquire the arrival times of waves. And then the travel time of the differential signal is calculated. The two-dimensional damage localization points can be obtained by analyzing the traveling path of the differential signal and together with the method of four point round technology. Experimental results prove that the damage location is reliable.