Acoustic emission (AE) and 4D X-ray computed tomography (4D XCT) were used simultaneously to study crack initiation and propagation in two different types of quartz-rich sandstones during the four-point bending experiments. Statistical analysis of the AE response indicated the failure mechanisms and their dynamics. The characteristic changes observed in the AE response defined the timing of the bending interruptions for XCT scanning to reveal the development of the crack. It was possible to quantitatively describe the developing cracks in their dimensions and volume and relate this information to the rate of decrease in the post-peak region of the material response. It could be concluded that the combination and concurrent use of AE and XCT techniques represents a highly effective and reliable instrument for observation, description, analysis of the crack propagation process, and rock disintegration in detail at a microscale level. With regard to the specific sandstones studied, Mšené sandstone is softer, respectively, less brittle, while Kocbeře sandstone is characterised by a more brittle behaviour accompanied by an AE signal with higher amplitudes compared to those of Mšené.

中文翻译：

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用于监测岩石中裂纹扩展的声发射和 4D X 射线微层析成像


在四点弯曲实验中，同时使用声发射 （AE） 和 4D X 射线计算机断层扫描 （4D XCT） 来研究两种不同类型的富石英砂岩中的裂纹萌生和扩展。AE 响应的统计分析表明了失败机制及其动态。在 AE 响应中观察到的特征变化定义了 XCT 扫描的弯曲中断时间，以揭示裂纹的发展。可以定量描述其尺寸和体积上正在发展的裂纹，并将此信息与材料响应的峰后区域的下降速率相关联。可以得出结论，AE 和 XCT 技术的结合和同时使用代表了一种非常有效和可靠的工具，用于在微观尺度上详细观察、描述、分析裂纹扩展过程和岩石崩解。就所研究的特定砂岩而言，Mšené 砂岩分别较软，脆性较低，而 Kocbeře 砂岩的特点是较脆，与 Mšené 砂岩相比，伴有振幅更高的 AE 信号。