| 李冬雪,杨康,何兆益,周翰林.混凝土中的声发射波速特性及其在源定位中的应用*[J].,2021,40(3):400-406 |
| 混凝土中的声发射波速特性及其在源定位中的应用* |
| Acoustic emission wave velocity character in concrete and its application in source localization |
| 投稿时间：2020-08-27 修订日期：2021-04-29 |
| 中文摘要: |
| 利用声发射技术监测受载混凝土裂缝发展特征的首要任务是对声发射源的准确定位。为了解混凝土中声发射的衰减规律，提高声发射源定位精度，本文开展了一系列室内试验，构建了考虑衰减现象的声发射波速修正模型，优化建立了基于修正波速的区域穷举定位法。结果表明：水灰比越小，基准波速越大，波速随距离的衰减越大。骨料粒径越大，基准波速越大，波速随距离的衰减越大。直线距离小于500mm时，可采用对数函数描述声发射波速与距离的定量关系，以此构建的波速修正模型满足工程精度要求。采用修正波速的区域穷举定位法对单轴压缩试验产生的裂缝进行定位时，定位点比时差定位法更接近裂缝实际位置，有效提高了定位精度。 |
| 英文摘要: |
| The primary task of monitoring the development character of concrete cracks under load by acoustic emission technology is to accurately locate acoustic emission sources. In order to understand the attenuation law of Acoustic emission in concrete and improve the positioning accuracy of acoustic emission source, a series of laboratory tests were carried out in this paper, a wave velocity correction model of acoustic emission considering attenuation phenomenon was constructed, and a regional exhaustive positioning method based on the corrected wave velocity was optimized. The results show that the smaller the water-cement ratio is, the larger the reference wave velocity is and the larger the attenuation of the wave velocity is with the distance. The larger the aggregate particle size is, the larger the base wave velocity is and the larger the attenuation of the wave velocity is with the distance. When the linear distance is less than 500mm, the logarithmic function can be used to describe the quantitative relationship between acoustic emission wave velocity and distance, so that the wave velocity correction model constructed can meet the requirements of engineering accuracy. The location point is closer to the actual location of the crack than the time difference method, which can effectively improve the location accuracy when using the zone exhaustion method with modified wave velocity to locate the crack. |
| DOI：10.11684/j.issn.1000-310X.2021.03.011 |
| 中文关键词: 混凝土 声发射 波速特征 源定位 |
| 英文关键词: concrete acoustic emission wave velocity character localization |
| 基金项目:国家重点研发计划（2018YFB1600200） |
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