Shannon complex wavelet and time reversal focusing based multi-damage imaging method on composite structures
Shannon complex wavelet and time reversal focusing based multi-damage imaging method on composite structures
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作者：
Y. Weiwei
研究了基于压电传感器阵列和主动Lamb波的结构损伤成像方法，解决了板状结构，特别是复合材料结构中Lamb波传播的多模态和模态转换问题，分析了多损伤散射信号的时反聚焦原理，基于该原理，提出了一种基于Shannon复小波和时间反转聚焦的信号合成成像方法，Lamb波响应信号到达时间的计算是信号合成中的一个重要问题。提出了兰姆波响应信号到达时间的计算方法，并在碳纤维复合材料板上对信号合成成像方法进行了验证，结果表明，该方法可以估计多个目标的位置，与30 cm×30 cm的监测区域相比，损伤定位误差不超过2 cm，可促进结构健康监测技术的实际应用。
A piezoelectric sensors array and active Lamb wave based structural damage imaging method was researched which was helpful to overcome the problems of damage monitoring with multi-mode and mode convention of Lamb wave propagation on plate-like structures,especially on those of composite materials.The principle of time reversal focusing of multi-damage scattering signals was analyzed.Based on this principle,a signal synthesis imaging method based on Shannon complex wavelet and time reversal focusing was proposed.In this method,calculation of time-of-arrival of Lamb wave response signals was an important issue to signal synthesis.A Shannon complex wavelet based time-of-arrival of Lamb wave response signals calculating method was proposed.The signal synthesis imaging method was validated on a carbon fiber composite plate.The result shows that this method could estimate the positions of multi-damages in the same monitoring area efficiently.Compared with the monitoring area of 30 cm×30 cm,the damage localization errors are no more than 2 cm.It can promote the practical applications of SHM technology.