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研究红外热像的多步骤滤波去噪技术以及基于红外热像的含水煤岩单轴压缩损伤特征分析.对试验室尺度煤岩试样进行了浸水饱和、单轴加载试验与红外热成像探测.对在试验中得到的红外热像,首先利用中值滤波去除脉冲噪声;然后利用小波多分辨分析算法去除热像中的相干噪声.研究结果表明:红外图像温度分布的不同模式表征了不同的损伤阶段,即随机分布的小尺度高低温区代表压密阶段;大尺度集中高温区是破坏的早期信号;贯通性大尺度高温区是破坏的临界点;孤立大尺度低温区表示由微破裂汇合而成的塑性损伤,是损伤局部化的表征;贯通的大尺度低温区代表宏观破坏.浸水煤样有较大的原始损伤;在压密、弹性、微裂纹稳定扩展、非线性破坏等各个峰前阶段的损伤尺度与扩展速率大于不含水煤岩;在峰值后只有应变软化阶段,以突然失稳形式破坏.
The multi-step filtering and denoising technology of infrared thermography and uniaxial compression damage analysis of water-bearing coal rock based on infrared thermography were carried out.The water-saturation, uniaxial loading test and infrared thermal imaging detection of coal-rock samples were carried out on laboratory scale. Firstly, the median noise is used to remove the impulse noise from the infrared thermography obtained in the experiment, and then the coherent noise in the thermal image is removed by using the wavelet multiresolution analysis algorithm. The results show that different modes of infrared image temperature distribution characterize different damage Stage, that is, random distribution of small-scale high and low temperature zone represents the compaction stage; Large-scale high-temperature zone is the early signal of destruction; Through large-scale high temperature zone is the critical point of destruction; Isolated large-scale low- The plasticity damage is the characterization of the damage localization. The large-scale low-temperature region that passes through represents the macroscopic damage, and the water-immersed coal sample has larger original damage. Before the various peaks such as compaction, elasticity, stable propagation of microcracks and nonlinear damage The scale and rate of damage in the stage are larger than that of the water-free coal, and only the stage of strain softening after the peak is destroyed by sudden failure.