TU458
国家应急管理部安全生产重特大事故防治关键技术资助项目（Sichuan-0011-2018AQ）；四川省科技计划资助项目（19YYJC2854）；四川省教育厅重点资助项目（18ZA0407）。
混凝土的物料组成影响着弹性波特征参数的衰减规律，该规律的研究对于提高工程安全检测精度意义重大。以0.1~0.25 mm，0.5~1 mm，1~2 mm和2~5 mm粒径的砂为骨料制成板状混凝土试件，利用声发射测量系统记录不同传播距离处的信号全波形，分析骨料粒径对弹性波衰减过程的影响机制。结果表明：弹性波的幅值按负指数函数衰减，衰减系数分别为0.043 75，0.025 79，0.021 85，0.018 71，即骨料粒径越小，则幅值的相对衰减速度越快；弹性波能量衰减规律也符合负指数函数，粒径越小，则能量衰减速度越快；弹性波的衰减速度与频率密切相关，随传播距离的增加，信号主频和频谱重心均近似线性下降，即高频信号部分衰减更快；此外，声发射信号振铃计数大致呈对数函数衰减。
The material composition of concrete affects the attenuation law of elastic wave characteristic parameters. The study of this law is of great significance for improving the accuracy of engineering safety detection. In this study, the plate-shaped concrete specimens werr made of sand with respective grain sizes of 0.1-0.25 mm, 0.5-1 mm, 1-2 mm and 2-5 mm, and the full waveform of the signals at different propagation distances was recorded by the acoustic emission measurement system to analyze the influence mechanism of particle size on the elastic wave attenuation process. The results show that the amplitude of the elastic wave is attenuated by the negative exponential function, and the attenuation coefficients are 0.043 75, 0.025 79, 0.021 85 and 0.018 71, respectively, so the smaller the particle size is, the faster the attenuation of amplitude is. The elastic wave energy attenuation law is also in accordance with the negative exponential function and the smaller the particle size, the faster the energy decay rate; the decay rate of the elastic wave is closely related to the frequency. As the propagation distance increases, the main frequency of the signal and the center of gravity of the spectrum will gradually decrease, that is, the high-frequency signal decays faster. In addition, the count of acoustic emission is also roughly a logarithmic function decay.
吴鑫,晏巧,彭雅雯,张婷婷,王雨.混凝土骨料粒径对弹性波特征参数衰减影响研究[J].重庆大学学报,2021,44(3):45-52.
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