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提出了一种应用Lamb波对板结构中多部位损伤源进行被动成像识别的方法.基于Mindlin板理论,推导了板结构中弥散性Lamb波频率-波数域的快速偏移方法,结合爆炸成像原理,对损伤源发出的Lamb波信号进行回传成像.由于损伤源的发生时刻未知,将使用不同假设发生时刻(即不同长度)的Lamb波信号生成一系列图像,通过最小熵原理从中确定最优图像,识别出损伤源的位置和发生时刻.进行了数值仿真研究来表明所提出方法的有效性.
A method of passive imaging recognition of multi-site damage sources in plate structure using Lamb wave is proposed. Based on Mindlin plate theory, a fast migration method of frequency-to-wave number domain of dispersive Lamb waves in plate structure is derived. Combining with the principle of explosion imaging, , The Lamb wave signal from the source of damage is back-propagated.As the origin of the damage source is unknown, a series of images will be generated using Lamb wave signals of different hypotheses (ie, different lengths) and the optimal one will be determined by the principle of minimum entropy Image, identify the location of the source of damage and the moment of occurrence.Numerical simulation studies have been carried out to show the effectiveness of the proposed method.