【摘要】 通过在单轴压缩下实施的声发射测试,研究焦作砂岩受20～1 200℃温度作用后的声发射演变过程;结合不同温度下砂岩的力学性质,通过声发射参数分析研究砂岩在不同受力阶段的声发射特点。研究表明:400℃以内温度对砂岩的声发射影响不太明显,在100℃后和600℃后声发射振铃累计数均发生急剧变化,100℃是砂岩裂纹扩展发育的门槛值,600℃后砂岩内部结构成分发生了变化,声发射现象较为明显。600～1 200℃时,砂岩呈现出明显的脆塑性转变现象,高温导致声发射信号的时间有所推迟,声发射信号增长率不断上升。1 200℃后,砂岩释放密集的声发射信号,呈现出塑性破坏特征。更多还原

【Abstract】 The acoustic emission evolution process of Jiaozuo sandstone with 20 ℃-1 200 ℃ temperatures is studied using acoustic emission(AE) test under uniaxial compression.By analyzing AE parameters and the mechanical properties of sandstone after high temperature,the AE characteristics of sandstone under different temperatures and different loading stages are explored.The results show that temperature has little effect on the acoustic emission of sandstone when temperature is less than 400 ℃.The AE ring-down accumulation counts change rapidly both at about 100 ℃ and 600 ℃ temperatures.It is shown that 100 ℃ is the threshold of crack growth for sandstone;and the internal structure composition of sandstone changes after 600 ℃;and acoustic emission phenomenon is very obvious.From 600 ℃ to 1 200 ℃,obvious brittle-plastic transition appears in sandstone.At the same time,the emergence of acoustic emission signals is delayed and the growth rate of acoustic emission signals rises because of high temperature.Sandstone releases intensive acoustic emission signals and presents plastic failure characteristics after 1 200 ℃.更多还原