摘要
在分析相控阵波束指向的控制过程与介绍相控阵结构健康监测原理的基础上,利用相控阵原理控制Lamb波的时间延迟使其在结构损伤处聚焦.通过比较结构健康状态与损伤状态的传感器响应信号,获取Lamb波损伤散射信号;采用相控阵技术控制损伤散射信号时间延迟得到不同方向的信号,进而实现对结构的多方位扫描,根据扫描信号特点,将各方向的监测结果信号采用灰度图像显示.该方法在铝板结构中实现损伤的定位成像,其不仅能够精确定位损伤位置,而且能够直观清晰显示结构损伤.
The phased array beam steering is controlled and the Lamb wave phased array theory is discussed in de-tail.Phased array technology is used to control the time delay of the Lamb wave and to make the Lamb wave focus on the structure damage. The damage scattered signal is extracted by comparing the health signal and the damage signal.The Lamb wave signal direction is controlled by utilizing the time delay to the excitation signals and the dam-age scattered signals and the structure is monitored in all orientations. The processed signals are shown on the mapped image in gray-scale. The gray-scale in the mapped image from dark to light corresponds to the amplitude from low to high.The location where the max amplitude of the signals lie is the damage location in the structure.Fi-nally,the proposed method is verified by an experiment on aluminum sheet structure and the result shows that it is effective to identify the damage position of structure and to display the damage clearly.
出处
《南京信息工程大学学报（自然科学版）》
CAS
2014年第5期420-425,共6页
Journal of Nanjing University of Information Science & Technology（Natural Science Edition）
基金
国家自然科学基金(51305211)
关键词
LAMB波
相控阵
结构健康监测
损伤图像
Lamb wave
phased array
structure health monitoring（SHM）
damage image
