不同温度作用后煤体单轴压缩声发射特征

(1.西安科技大学 安全科学与工程学院,陕西 西安 710054; 2.西安科技大学 陕西省煤火灾害防治重点实验室,陕西 西安 710054)

煤样; 温度; 应力; 单轴压缩; 声发射

Acoustic emission characteristics of coal samples after different temperature under uniaxial compression
XIAO Yang1,2,LIU Zhi-chao1,2,CHEN Long-gang1,2,REN Shuai-jing1,2,ZHAO Shuai1,2,ZHOU Yi-feng1,2

(1.College of Safety Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 2.Shaanxi Key Laboratory of Prevention and Control of Coal Fire,Xi'an University of Science and Technology,Xi'an 710054,China)

coal specimens; temperature; stress; uniaxial compression; acoustic emission

DOI: 10.13800/j.cnki.xakjdxxb.2019.0105

备注

为研究温度对煤体力学特性的影响规律,采用MTS-880试验系统和声发射检测系统对经过不同温度处理的煤体进行单轴压缩全过程声发射测试。结果 表明,随着应力的增加,经不同温度处理的各组煤体的累积声发射数量也随之增加,而经不同温度处理的各组煤体所积累声发射存在明显差异,这主要是由于温度使得煤体内部结构发生变化所致。通过区别各组煤体不同时段的声发射特征,不同温度条件对煤体的破坏存在明显差异,随着温度的升高煤体应力-应变全过程中压密过程延长,煤体弹性模量和抗压强度在温度作用下先增后减,140 ℃时为最大值; 而随着温度升高,声发射频率表现愈发离散,声发射振铃数与能量在80 ℃时达到最大值。实验结果可为探究热效应对煤体作用机理提供一定的理论依据。

In order to study the influence of temperature on coal properties,the MTS-880 test system and acoustic emission testing system were used to carry out the uniaxial compression test of coal body after different temperature treatment.The results show that with the increase of stress,the amount of cumulative acoustic emission of each coal body increases with different temperatures,and there is a significant difference in the acoustic emission from each coal body treated at different temperatures,which is mainly due to the change of the internal structure of the coal body.With the increase of temperature,the densifying process is extended during stress-strain process of coal,and the modulus of elasticity and the compressive strength of coal increase gradually,then decreases and reach the maximum at 140 ℃ under the action of temperature.With the increase of temperature,the acoustic emission frequency is more discrete,and the number and energy of acoustic emission reaches the maximum at 80 ℃.The experimental results provide theoretical basis for exploring the mechanism of thermal effect on coal.