兰姆波结构健康监测中的概率损伤成像  

Probability damage imaging in Lamb wave structural health monitoring

作　　者：张海燕[1] 马世伟[1] 冯国瑞[1] 于建波[1] 

机构地区：[1]上海大学通信与信息工程学院特种光纤与光接入网省部共建重点实验室,上海200072

出　　处：《声学学报》2012年第4期401-407,共7页Acta Acustica

基　　金：国家自然科学基金(11074164;10874110;61171145);上海市教委创新基金(11YZ17)资助项目

摘　　要：应用概率成像方法对兰姆波结构健康监测中板的损伤进行识别。根据兰姆波损伤散射信号的传播时间以及传感器网络中一对发射-接收传感器的空间位置来确定一个椭圆轨迹,该轨迹显示了损伤可能出现的位置。将监测区域均匀网格化,计算各网格节点到椭圆轨迹的最短距离,将此距离映射为损伤出现的概率。采用灰度等级对所有网格节点处的概率值进行量化,则由每一个发射接收传感器对就确定了一个灰度图像。为了突出损伤,应用图像融合技术对传感器网络中所有发射接收传感器对所构成的灰度图像进行融合。对铝板中横穿孔损伤的实验结果显示了该方法能够有效地确定损伤的位置和范围,有助于推动兰姆波结构健康监测的实用化。A probability-based imaging approach is employed to identify the damage in plate for Lamb wave structural health monitoring.In this study,an ellipse locus,indicating possible locations of the damage,is determined by the time-of-flight of damage-scattered Lamb wave signals and the spatial position of a transmitter-receiver pair in the sensor network.The inspection area is evenly meshed.The shortest distances between each mesh node in the inspection area and the ellipse locus are calculated.We map the distance to the probability of the damage occurrence,which leads to a grey image for each transmitter-receiver pair when the probabilities are quantified at all mesh nodes with a grey-scale. Individual grey images from all transmitter-receiver pairs of the sensor network are fused to accentuate the damage by employing the image fusion technique.The probability-based imaging approach is experimentally verified by evaluating through-thickness hole damage in an aluminium plate.It is suggested that the approach is an effective way for identifying the location and extent of damage,helping to promote the practical use of Lamb wave structural health monitoring.

关 键 词：结构健康监测 成像方法 兰姆波 概率值 损伤 传感器网络 空间位置 灰度图像 

分 类 号：O429[理学—声学]