论文部分内容阅读
为了有效地检测双层层压复合材料中损伤的位置及其形状,提出了一种基于波数分析的激光超声损伤检测方法。在声场互易假设的基础上实现了波场可视化;分析了损伤对材料中超声波波数的影响;采用短空间傅里叶变换的方法,通过时域和频域的局部波数估计算法实现双层层压复合材料的损伤的定位成像;为了充分利用不同时刻和不同频率下的波场信息,减弱时间和频率选取对损伤成像产生的影响,采用了一种波数滤波损伤成像算法,通过对不同时刻的波场进行波数分析,根据不同波数所占的权值不同,采用波数域内加窗的方法滤除健康信号,并通过二维能量图实现损伤的定位成像。
In order to effectively detect the location of damage and its shape in double-layer laminated composites, a method of laser ultrasonic damage detection based on wave number analysis is proposed. Based on the assumption of reciprocal sound field, the wave field visualization is realized. The influence of damage on the ultrasonic wave number in the material is analyzed. By using the method of short-space Fourier transform, the double-layer In order to make full use of wavefield information at different time and different frequencies and to reduce the impact of time and frequency selection on the damage imaging, a wave number filtering damage imaging algorithm is adopted, Wavefield analysis of wave number, according to the different weights of different wavenumbers, using the method of windowing within the wave number domain filter out the health signal, and through the two-dimensional energy map to achieve the positioning of the damage imaging.