Study on the characteristics of the acoustic and the thermal effects of sandstone under uniaxial compression condition

Abstract

Acoustic emission and infrared radiation measurements were carried out on medium sandstone, fine sandstone and siltstone in the coal measures of the Ordos Basin under uniaxial compression, the stress, the acoustic energy and the average infrared radiation temperature (AIRT) versus time evolution of characteristics were analyzed, the acoustic and the thermal effects characteristics of different granular sandstones during the rupture process were studied.The results show that the AIRT in the different areas of the same sandstone has the same trend in the compaction and elasticity phase,but the tendency is different in the plasticity and damage stages.It generally shows a wave downward trend; and the temperature in the middle is higher than that in the upper and lower parts.The temperature changes in different sandstones are related to energy accumulation and dissipation,and the overall trend of AIRT on the sandstone surface shows a wave downward trend, acoustic emission (AE) is not obvious at the beginning ,but it raise rapidly during the later stage of plasticity, there are still a large number of AE events after the peak; the precursor of infrared radiation priority to the acoustic emission warning, the average infrared warning time of middle sandstone is 20.533s, fine sandstone is 6.516s ahead, and siltstone is 6.4s, but the sensitivity of the acoustic emission is higher than that of the infrared radiation.The acoustic and the thermal effects of sandstone is closely related to the particle size,the larger the particles, the more pronounced the acoustic thermal effects.The sensitivity of the acoustic thermal effect is in the order of medium sandstone, fine sandstone and siltstone.

Keywords

• the uniaxial compression
• sandstone
• the acoustic thermal effects
• sensitivity