深部复合煤岩卸荷破裂热红外辐射机理及多场耦合模型研究

Deep composite coal rock unloading deformation and fracture process is accompanied by heat, electromagnetic energy release. By designing detection system based on new sensor, change rules of parameters of mechanics, electrical, thermal, thermal infrared radiation signal and so on in the process of deep composite coal rock deformation and fracture are analyzed through the deep coal rock sample complete experiment under different unloading mode and conditions.Coal rock unloading destruction constitutive model is established. Composite damage factor is proposed, compound unloading of coal and rock damage evolution equation and its failure criterionis are derived based on the principle of minimum energy dissipation.The relations is studied between thermal infrared radiation and unloading of coal and rock mechanical damage mechanism.It is studied in this issue that unloading process of thermal infrared radiation temporal evolution, characteristics and propagation in deep coal rocks. It is to research into coal thermal infrared radiation unloading mechanism; coupling path among temperature field, electromagnetic field and stress and three physical interaction mechanisms.Coupling model among electromagnetic field, temperature field and stress field in the process of coal rock unloading deformation and fracture is proposed firstly, and on the basis of the model the precise coal rock unloading instability energy criterion is established. By the experiment the created mathematical model parameters are calculated, verificated, corrected. The deep coal rock dynamic disaster evolution mechanism and prediction theory are further revealed which have important and realistic meanings through the research.

深部复合煤岩卸荷变形破裂过程伴随热能、电磁能等能量的释放。设计基于新型传感器的检测系统；通过完整的深部复合煤岩试样在不同卸荷方式、条件下的变形破裂实验，对煤岩卸荷过程中力学、电性、热力学、红外辐射信号等参数变化规律进行研究；建立煤岩卸荷破坏的本构模型；提出复合损伤因子，基于最小耗能原理推导复合煤岩卸荷损伤演化方程，推导其破坏准则；研究热红外辐射与煤岩力学卸荷破坏机制的关系；研究卸荷过程中热红外辐射时空演化规律、特征及在深部煤岩中的传播规律；深入研究深部煤岩卸荷热红外辐射机理；研究温度场、电磁场、应力场三个物理场之间的耦合路径及相互影响机制；首次提出建立深部复合煤岩卸荷变形破坏过程中的电磁场、温度场、应力场耦合模型，并在此基础上建立精确的煤岩卸荷失稳判据。通过实验对建立的数学模型参数进行计算、验证、修正。课题的研究对于进一步深入揭示深部煤岩动力灾害演化机理及预测预报具有重要的理论与现实意义。

深部复合煤岩卸荷变形破裂过程伴随热能、电磁能等能量的释放。利用热红外辐射规律可实现对煤岩动力灾害的非接触连续监测。研制了基于DSP的深部复合煤岩卸荷变形破裂多参数监测系统，研制了电磁、电荷、温度信号监测模块，设计了基于LabVIEW的上位机监测软件。采用FLAC3D构建了深部复合煤岩在不同组合比、不同卸围压速率、不同物性参数的条件下三轴卸荷仿真模型，研究轴向应力、偏应力、应变的变化规律，实验与仿真具有一致性；针对复合煤岩在不同卸荷速率、不同围压条件下进行三轴卸荷试验，研究应力、应变变化规律及初始围压与抗压强度关系。在不同加卸速率条件下对复合煤岩进行循环加卸荷实验，结果表明：不同加卸荷速率下复合煤岩温度变化规律具有较强的一致性，加卸速率越大，温升越高；弹性能密度随轴向荷载增长而增长，加卸速率越大滞回效应能量密度增长越平滑，加卸速率越小复合煤岩塑性耗散能倾向于岩石能量特性。研究深部复合煤岩三轴加载-卸荷状态下热红外辐射传播及衰减规律，结果表明：热红外辐射在纵向从煤体中心向两侧岩体呈指数衰减，在横向以不同半径从煤体中心向外衰减；在煤体中衰减速度比在岩体中快；卸围压速率越大，热红外辐射温度峰值到达时间越短，峰值越大，随应力增加不断升高。研究复合煤岩试样加载变形破裂过程中电磁、电荷、温度信号变化规律；基于SET(应力-电磁-温度)耦合模型，结合复合损伤因子及电磁、电荷相关性关系推导了SCT(应力-电荷-温度)耦合模型。研究了复合煤岩受载变形破裂表面红外辐射温度的演化规律。结合损伤力学、电磁场等交叉学科理论，推导了复合煤岩受载变形破裂温度场、应力场、电磁场多物理场耦合数学模型，建立了仿真模型，实验与仿真结果一致。推导了深部复合煤岩在加卸荷过程中温度场、应力场、电磁场多场耦合模型，研究多物理场变化规律及耦合机制，实验与仿真结果一致。研究成果对于进一步深入揭示深部煤岩动力灾害演化机理及预测预报具有重要的理论与现实意义。