The changes in the acoustic emission signals of sandstone after treatment at different high temperatures are examined in this study. The results show that there is a critical point on the cumulative energy curve of the acoustic emission signals (almost between 60 and 90% of the ratio of the loading time and the total loading time), which can be used to identify the failure of sandstone that has been damaged by exposure to a temperature of 900°C. As the temperature increases, the position of the critical point gradually changes, which indicates that high temperatures increase the plasticity of rock, and this gradually reduces the brittleness. The changes in b-value of acoustic emission shows that the transition behavior of rock from brittleness to plasticity is more obvious at temperatures higher than 600°C, and the large-scale micro cracking takes place at that temperature range, which is the main reason for the weakening and brittleness and the strengthening of plasticity of the sandstone.

中文翻译：

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通过声发射信号识别热损伤砂岩的关键失效信息

本研究考察了不同高温处理后砂岩声发射信号的变化。结果表明，声发射信号的累积能量曲线上存在一个临界点（几乎在加载时间与总加载时间之比的 60% 到 90% 之间），可用于识别砂岩的失效。已因暴露于 900°C 的温度而损坏。随着温度的升高，临界点的位置逐渐变化，说明高温使岩石的塑性增加，而脆性逐渐降低。声发射b值的变化表明，岩石从脆性到塑性的转变行为在高于600℃时更为明显，