基于声发射技术的混凝土动态劈拉试验研究

为了研究混凝土材料在受拉状态时的动态力学性能,采用新型动态无损检测声发射技术进行了不同加载速率下(10^-5/s ,10^-4/s,10^-3/s,10^-2/s)混凝土劈拉试验,根据实时采集的声发射数据建立了不同加载速率下应力及同步声发射参数与时间的对应关系,并在此基础上分析了混凝土在劈拉破坏全过程中的能量释放特性及规律。结果表明混凝土在劈裂抗拉破坏过程中不具有典型的三阶段特征,加载前期产生的声发射信号较微弱,材料达到峰值应力时能量信号突然急剧上升;采集的声发射数据能真实地反映混凝土劈拉破坏特性。

Dynamic Splitting Tensile Test on Concrete By Using Acoustic Emission Technology

To research the dynamic mechanical properties of concrete in tension,splitting tensile tests were per-formed on concrete under different strain rates(1 0 -5 /s,1 0 -4 /s,1 0 -3 /s,1 0 -2 /s)using nondestructive acoustic e-mission technology.According to the real-time acquired acoustic emission data,the corresponding relation between acoustic emission parameter and stress-time curves under different loading rates were established,and the charac-teristics and regularities of concrete’s energy release in the whole process of splitting tensile damage were analysed. Results showed that typical characteristics of three phase did not happen in the process of splitting tensile damage, emission signal was weak at the early stage of loading,and energy signal suddenly rose sharply when the concrete material reached peak stress.The acquired acoustic emission data could reflect the real splitting tensile damage of concrete.