混凝土声发射信号频率特征与强度参数的相关性试验研究  

Experimental research on relationship between frequency characteristics of acoustic emission and strength parameter in concrete

作　　者：郭庆华[1,2] 郤保平[1] 李志伟[1] 郑晓琛[1] 田俊斌[1] 朱合华[2] 

机构地区：[1]太原理工大学地下工程系,山西太原030024 [2]同济大学地下建筑与工程系,上海200092

出　　处：《中南大学学报（自然科学版）》2015年第4期1482-1488,共7页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51478345);山西省青年科学基金资助项目(2011021023-2);山西省高校科研开发项目(20111004)~~

摘　　要：对不同强度指标的混凝土试块进行抗压试验,应用声发射及其定位技术对抗压试验全过程进行同步监测,分析混凝土受载破坏过程中声发射频率特征参数与混凝土强度指标的关系,研究混凝土受载破坏过程中内部裂纹的三维空间演化规律。研究结果表明:混凝土强度指标影响混凝土声发射信号频率特征参数。结合荷载-位移曲线对声发射振铃计数率和能率进行分析,发现C10和C20混凝土(低强度混凝土)声发射信号主要集中于弹性阶段初期和中期;C30和C40混凝土(中等强度混凝土)声发射信号处于受压全过程,声发射活跃期处于极限荷载处。通过对混凝土声发射事件进行空间三维定位,从微观上探明受载混凝土裂纹的萌生、发展和贯通的演化规律,对受载混凝土内部结构的变化有了直观的认识。The concrete samples with different strength parameters were tested under uniaxial load. During the whole testing process was monitored synchronously through the acoustic emission（AE） system. The relationship between frequency characteristics parameters of acoustic emission signals and the strength parameters of concrete samples was analyzed. The three-dimensional space evolution of inner crack of concretes was researched in the failure process. The experimental results show that the AE frequency characteristic parameters are affected by the strength parameters of concrete. The AE ring count rate and energy rate are analyzed on the basis of the load-displacement curve and the results show that the AE signals of C10 and C20 concrete（low strength concrete） mainly concentrate on the initial and mid-term stage of elastic domains while the AE signals of C30 and C40 concrete（medium strength concrete） are in the whole failure process and the active stage is at the ultimate load. The test on the 3D-distribution of AE signals, the evolution from generation and growth to connectivity of cracks is proved from the microcosmic point. The experimental study provides an intuitive understanding of the inner structural changes of concrete in the failure process.

关 键 词：混凝土 声发射 强度指标 裂纹 空间演化 

分 类 号：TU528.31[建筑科学—建筑技术科学]