煤破坏过程中的温度演化特征实验研究

 以红外热像仪和数字散斑相关方法作为试验观测手段，对一种煤试件进行实验研究，观测和分析煤试件从变形到破坏过程中的变形演化、温度演化及二者的对应变化关系。研究结果表明：(1) 煤试件变形场演化主要体现为初期的均匀变形演化到加载峰值前的变形集中带形成，加载峰后阶段主要为变形集中带的加速滑动；(2) 煤试件温度场演化在加载峰前由于受压应力作用，内部质点间距发生改变的热力耦合效应引起温度上升，在加载峰后阶段由于变形集中带内煤体受拉剪作用及变形集中带的滑动，引起温度降低；(3) 煤试件在变形破坏过程中存在明显的温度场变化，且变形集中带内、外温度演化特征相似，加载峰前阶段温度增加，加载峰后阶段温度降低，但变形集中带内温度总体高于带外温度。

EXPERIMENT STUDY OF TEMPERATURE EVOLUTION CHARACTERISTICS DURING DEFORMATION AND DESTRUCTION PROCESS OF COAL

The evolution characteristics of deformation fields and temperature fields are inspected and analyzed by using the digital speckle correlation method and infrared thermal imager. The test material is a kind of coal and the specimens are loaded by uniaxial test machine. The analytical results show that：(1) The deformation field evolution of coal specimen is divided into two phases：initial uniform deformation evolution to deformation localization at pre-peak loading stage，and deformation concentration in the localization band at post-peak loading stage. (2) The temperature evolution of coal specimen is divided into two phases：temperature rises due to internal particle spacing change caused by thermo-mechanical coupling effect at pre-peak loading stage；temperature decreases due to the tensile-shear effect and the sliding effect of deformation localization band at post-peak loading stage. (3) The temperature change is obvious in the deformation and destruction process of coal specimens；and the temperature evolution characteristics are similar inside and outside the deformation concentration band. The temperature increases at pre-peak loading stage and decreases at post-peak loading stage. The temperature inside the deformation localization band is higher than that outside the deformation localization band.