DAMAGE ASSESSMENT IN CONCRETE USING QUANTITATIVE ACOUSTIC EMISSION
DAMAGE ASSESSMENT IN CONCRETE USING QUANTITATIVE ACOUSTIC EMISSION
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DOI：
10.1061/(asce)0733-9399(1991)117:11(2681
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发表时间：
1991-11
期刊：
影响因子：
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通讯作者：
C. Ouyang;E. Landis;Surendra P. Shah
中科院分区：
文献类型：
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作者：
C. Ouyang;E. Landis;Surendra P. Shah
声发射 (AE) 是受力材料中应变能的局部快速释放。最近开发了定量声发射测量技术来估计单个微裂纹的位置、尺寸、方向和断裂模式。定量 AE 技术应用于四点荷载下素混凝土梁的实验室研究。加载中心切口和偏心切口梁以分别产生 I 型和混合模式失效。使用AE地震矩张量表示，微裂纹被表征为I型、II型或混合型。将微裂纹模式与可见裂纹模式进行比较。大多数微裂纹平面与 I 型宏观裂纹（中心缺口）的拉应力垂直，而混合模式宏观裂纹（偏心缺口）的微裂纹平面分布相对均匀。即使对于中心切口梁，也观察到大量混合模式的微裂纹，这表明微裂纹的断裂机制可能与主要宏观力学裂纹不同。结果表明，声发射测量可以为评估损坏提供潜在的强大工具。
An acoustic emission (AE) is a localized rapid release of strain energy in a stressed material. Quantitative acoustic emission measurements techniques have recently been developed to estimate the location, size, orientation, and fracture mode of individual microcracks. Quantitative AE techniques were applied to a laboratory study of plain concrete beams under four point loading. Center-notched and off-center-notched beams were loaded in order to produce, respectively, mode I and mixed mode failure. Using AE seismic moment tensor representation, microcracking was characterized as mode I, mode II, or mixed mode. The mode of microcracking was compared to the mode of the visible crack. Most microcrack planes were in a direction normal to the tensile stress for a mode I macrocrack (center-notched), whereas microcrack planes were relatively uniformly distributed for a mixed-mode macrocrack (off-center notched). A large number of mixed-mode microcracks were observed even for the center-notched beam indicating that fracture mechanisms of microcracks may differ from the main macromechanical crack. It is shown that AE measurements can provide a potentially powerful tool in assessing damage.