Analysis of Dynamic Tensile Process of Fiber Reinforced Concrete by Acoustic Emission Technique  

作　　者：WANG Yan CHEN Shijie GE Lu ZHOU Li HU Hongxiang 王岩;CHEN Shijie;GE Lu;ZHOU Li;HU Hongxiang(College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China;Shenzhen Municipal Design ＆Research Institute Co.,Ltd,Shenzhen 518029,China;ChongQing Municipal Designing Research Institute,ChongQing 400020,China)

机构地区：[1]College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China [2]Shenzhen Municipal Design&Research Institute Co.,Ltd,Shenzhen 518029,China [3]ChongQing Municipal Designing Research Institute,ChongQing 400020,China

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2018年第5期1129-1139,共11页武汉理工大学学报（材料科学英文版）

基　　金：Funded by the National Natural Science Foundation of China(No.51009058);Postdoctoral Science Foundation of China(No.2011M501160);the University Natural Science Research Project of Jiangsu Province(No.13KJD560002);the Doctoral Research Start-up Fund of Jinling Institute of Technology(No.Jit-b-201321)

摘　　要：The fiber reinforced concrete has good dynamic mechanical properties. But corresponding research lacks the dynamic damage characteristics of the polypropylene fiber（fiber of low elastic modulus） and steel fiber（fiber of high elastic modulus） reinforced concrete under medium strain rate（10-6 s-1-10-4 s-1）. In order to study the effect of strain rate on the damage characteristics of fiber reinforced concrete during the full curve damage process, the real time dynamic acoustic emission（AE） technique was applied to monitor the damage process of fiber reinforced concrete at three strain rates. The AE wavelet energy spectrum in ca8 frequency band and average AE peak frequency at three strain rates were analyzed. With the accumulation of damage, the AE wavelet energy spectrum in ca8 frequency band increased first and then decreased, and the average AE peak frequency increased gradually. With the increase of strain rate, the AE wavelet energy spectrum in ca8 frequency band and average AE peak frequency decreased gradually. The polypropylene fiber content has more obvious effect on the Dynamic increase factor（DIF） of the peak stress than the steel fiber content. The theoretical basis was provided for the monitoring of dynamic damage of fiber reinforced concrete based on the AE technique.The fiber reinforced concrete has good dynamic mechanical properties. But corresponding research lacks the dynamic damage characteristics of the polypropylene fiber（fiber of low elastic modulus） and steel fiber（fiber of high elastic modulus） reinforced concrete under medium strain rate（10-6 s-1-10-4 s-1）. In order to study the effect of strain rate on the damage characteristics of fiber reinforced concrete during the full curve damage process, the real time dynamic acoustic emission（AE） technique was applied to monitor the damage process of fiber reinforced concrete at three strain rates. The AE wavelet energy spectrum in ca8 frequency band and average AE peak frequency at three strain rates were analyzed. With the accumulation of damage, the AE wavelet energy spectrum in ca8 frequency band increased first and then decreased, and the average AE peak frequency increased gradually. With the increase of strain rate, the AE wavelet energy spectrum in ca8 frequency band and average AE peak frequency decreased gradually. The polypropylene fiber content has more obvious effect on the Dynamic increase factor（DIF） of the peak stress than the steel fiber content. The theoretical basis was provided for the monitoring of dynamic damage of fiber reinforced concrete based on the AE technique.

关 键 词：acoustic emission steel fiber polypropylene fiber strain rate acoustic emission wavelet energy spectrum peak frequency 

分 类 号：TU528[建筑科学—建筑技术科学]