A novel method combining the time-reversal method (TRM) with wavelet analysis was proposed for damage imaging in mesoscale concrete modeling. The damage was imaged by the convergence of time-reversed wave signals after wavelet analysis. Through numerical study, three concrete models of different damage sizes were built with randomly distributed aggregate particles. The time-reversal process was simulated using the reverse damage-scattered ultrasonic wave signals as excitations recorded by the sensors. Then, the wavelet analysis was employed to extract certain frequency component, which can enhance detection precision and the signal-to-noise ratio. The damage imaging showed clearly the location of the defect. The results from experimental testing also demonstrated that this detection technique is an efficient and effective method for damage imaging in mesoscale concrete.

中文翻译：

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基于超声时间反演技术的中尺度混凝土模型损伤成像

提出了一种将时间反转方法与小波分析相结合的新方法，用于中尺度混凝土模型的损伤成像。小波分析后，通过时间反转波信号的收敛来成像损伤。通过数值研究，用随机分布的骨料颗粒建立了三种不同破坏大小的混凝土模型。使用反向损伤分散的超声波信号作为传感器记录的激励来模拟时间反向过程。然后，通过小波分析提取一定的频率成分，可以提高检测精度和信噪比。损伤成像清楚地显示了缺陷的位置。