In this work, fracture monitoring of steel and GFRP bars reinforced concrete beams in flexure is investigated by using non-destructive acoustic emission (AE) and digital image correlation (DIC) techniques. The combined methodology provides complementary information from 'the ear' aided by the AE and from 'the eye' aided by the DIC. AE waveform parameters of the number of AE hits and their amplitudes, cumulative signal strength (CSS), average frequency, and rise-time successfully pick-up the divergent cracking initiation and fracture progression in steel-reinforced concrete (RC) and GFRP-RC beams. AE-XY plots and longitudinal strain profiles obtained from DIC give an early, online, and real-time representation of progressive AE activity and strains inside concrete much before it is visible to the naked eye. AE in conjunction with DIC was able to efficaciously depict the micro-and-macro cracks evolution and their advancement in steel-RC and GFRP-RC at various stages of loading Moreover, DIC identified critical damage areas as a function of loading periods, while AE was capable of monitoring the damage process and revealed changes in the overall behavior. It is successfully demonstrated that combined AE and DIC monitoring can enhance non-destructive monitoring skills in RC structures involving widely different steel and GFRP bars as reinforcements and depict efficaciously their fracture/cracking behavior.

中文翻译：

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使用声发射和数字图像相关技术对钢和 GFRP 钢筋混凝土梁的断裂进行监测

在这项工作中，通过使用无损声发射 (AE) 和数字图像相关 (DIC) 技术，研究了受弯钢筋和 GFRP 钢筋混凝土梁的断裂监测。组合方法提供来自 AE 辅助的“耳朵”和 DIC 辅助的“眼睛”的补充信息。AE 冲击次数及其幅度、累积信号强度 (CSS)、平均频率和上升时间的 AE 波形参数成功地获取了钢筋混凝土 (RC) 和 GFRP-RC 中不同的开裂起始和断裂进展梁。从 DIC 获得的 AE-XY 图和纵向应变曲线在肉眼可见之前提供了混凝土内部渐进式 AE 活动和应变的早期、在线和实时表示。AE 与 DIC 结合能够有效地描述钢-RC 和 GFRP-RC 在不同加载阶段的微观和宏观裂纹演变及其进展 此外，DIC 将临界损伤区域确定为加载周期的函数，而 AE能够监控损坏过程并揭示整体行为的变化。成功地证明，AE 和 DIC 联合监测可以提高钢筋和 GFRP 钢筋作为钢筋的 RC 结构的无损监测技能，并有效地描述它们的断裂/开裂行为。而 AE 能够监控损坏过程并揭示整体行为的变化。成功地证明，AE 和 DIC 联合监测可以提高钢筋和 GFRP 钢筋作为钢筋的 RC 结构的无损监测技能，并有效地描述它们的断裂/开裂行为。而 AE 能够监控损坏过程并揭示整体行为的变化。成功地证明，AE 和 DIC 联合监测可以提高钢筋和 GFRP 钢筋作为钢筋的 RC 结构的无损监测技能，并有效地描述它们的断裂/开裂行为。