首页|堆石混凝土劈裂抗拉破坏过程中声发射特征分析

堆石混凝土劈裂抗拉破坏过程中声发射特征分析

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  • 国家科技期刊平台
  • NETL
  • NSTL
  • 万方数据
  • 维普
[目的]通过研究堆石混凝土(RFC)和自密实混凝土(SCC)在劈裂抗拉破坏过程中产生的声发射信号，并进一步确定最终的裂缝形态，有助于深入了解RFC和SCC的劈裂破坏特征，从而确保结构的可靠性和安全性。[方法]制作了边长为600 mm的RFC和SCC立方体试件，研究了 RFC和SCC在劈裂抗拉破坏过程中声发射参数(振铃计数和累计振铃计数)与位移荷载曲线的关系;利用声发射信号的统计方法(RA和AF)分析确定了 RFC和SCC裂纹演化特征;基于RA-AF值的混合高斯模型(GMM)辨识了劈裂抗拉破坏过程中RFC和SCC的开裂模式(拉伸型开裂或剪切型开裂)。[结果]结果显示:在劈裂破坏过程中，RFC声发射振铃计数分布不均，呈现分段式变化特点，累计振铃计数呈现明显阶梯状上升，SCC声发射振铃计数分布均匀，累计振铃计数平缓上升;RFC和SCC的拉伸型裂纹区域对应RA-AF数据点向AF轴靠拢，剪切型裂纹区域对应RA-AF数据点向RA轴靠拢，均表现出明显的原点集中现象。[结论]结果表明:(1)RFC和SCC劈裂抗拉破坏强度分别为其立方体抗压强度的0。065、0。067;(2)在劈裂抗拉破坏过程中，RFC的破坏模式以拉伸型开裂为主，占89。4％，SCC以剪切型开裂主，占53。6％;(3)利用GMM方法，通过概率密度估计能对裂纹的分类特点进行更精确的捕捉。
Analysis of acoustic emission characteristics during the splitting tensile failure process of rock filled concrete
[Objective]Investigating acoustic emission characteristics during the splitting tensile failure process of rock filled con-crete(RFC)and self-compacting concrete(SCC),and further determining the ultimate crack patterns are helpful to understand the splitting failure characteristics of RFC and SCC,so as to ensure the reliability and safety of the structure.[Methods]Cubic specimens with a side length of 600 mm were prepared for RFC and SCC.The relationship between acoustic emission parameters(ringing counts and cumulative ringing counts)and displacement-load curves during the splitting tensile failure of RFC and SCC was investigated.Statistical method(RA and AF)were employed to analyze the crack evolution characteristics based on acoustic emission signals.Furthermore,a Hybrid Gaussian Mixture Model(GMM)based on RA-AF values was used to identify the crack-ing modes(tensile cracking or shear cracking)of RFC and SCC during splitting tensile failure.[Results]The results show that in the process of splitting failure,the distribution of RFC acoustic emission ringing count is uneven,showing the characteristics of segmented change.The cumulative ringing count shows an obvious step-like rise.The distribution of SCC acoustic emission rin-ging count is uniform,and the cumulative ringing count rises gently.The tensile crack area of RFC and SCC corresponds to the RA-AF data point moving closer to the AF axis,and the shear crack area corresponds to the RA-AF data point moving closer to the RA axis,both of which show obvious origin concentration.[Conclusion]The conclusion are as follows:(1)The splitting tensile strength of RFC and SCC is 0.065 and 0.067 times their respective cubic compressive strengths.(2)In the process of splitting tensile failure,the failure mode of RFC is mainly tensile cracking,accounting for 89.4％,and SCC is mainly shear cracking,accounting for 53.6％.(3)Using the GMM method,the classification characteristics of cracks can be more accurately captured by probability density estimation.

rock filled concreteself-compacting concretesplitting tensileacoustic emissionRA-AFGMMmechanical prop-ertiesdeformation

罗滔、黄陈霖、张天祺、金峰

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西京学院 陕西省混凝土结构安全与耐久性重点实验室,陕西西安 710123

西北农林科技大学 水利与建筑工程学院,陕西杨凌 712100

清华大学 水圈科学与水利工程全国重点实验室,北京 100084

堆石混凝土 自密实混凝土 劈裂抗拉 声发射 RA-AF GMM 力学性能 变形

国家自然科学基金青年基金项目国家自然科学基金重点项目陕西省青年科技新星项目清华大学水圈科学与水利工程全国重点实验室开放基金项目

51909223520390052022KJXX-85sklhse-2023-C-04

2024

10.13928/j.cnki.wrahe.2024.01.004

水利水电技术(中英文)
水利部发展研究中心

水利水电技术(中英文)

CSTPCD北大核心
影响因子：0.456
ISSN：1000-0860
年,卷(期)：2024.55(1)
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