考虑吸附作用的含气煤本构关系  

CONSTITUTIVE RELATION FOR GAS-FILLED COAL CONSIDERING ADSORPTION

作　　者：祝捷[1,2] 姜耀东[1,2] 赵毅鑫[1,2] 

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083 [2]中国矿业大学(北京)煤炭资源与安全开采国家重点实验室,北京100083

出　　处：《岩石力学与工程学报》2009年第A02期3296-3301,共6页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家科技支撑计划课题(2006BAK03B06);国家自然科学基金资助项目(50704034);煤炭资源与安全开采国家重点实验室自主研究课题资助

摘　　要：利用混合物理论本构建模的方法,给出含气煤饱和混合物的本构方程,方程中混合物组分体积分数反映煤体内部结构的变化,并建立组分应力与真实应力之间的联系。考虑含气煤为各向同性弹性体,根据弹性能与表面能的变化相等条件下吸附作用引起的煤体体积变形,得出含气煤饱和混合物中各组分体积分数,进而由本构方程推导三轴应力条件下含气煤的应力–应变关系。通过考察不同吸附性气体的煤样应力–应变曲线,分析吸附作用对含气煤本构关系的影响,并将试验曲线与理论预测进行比较。研究结果表明,含气煤试验曲线与理论值吻合良好,理论公式可用于描述与气体吸附性有关的煤体变形差异。即使煤的骨架结构满足虎克弹性体本构关系假定,在孔隙率和孔隙压力相同条件下,气体吸附性的差异仍将改变含气煤的应力–应变关系。The constitutive equation is given by means of a constitutive modeling approach based on the theory of mixtures.The volume fraction of each constituent of the saturated mixtures can describe pore structure of coal and connect constituent stress with true stress.Assuming isotropic elastic behavior and that the change of the elastic energy equals the change of surface energy,gas adsorption-induced coal swelling and the volume fraction of each constituent of the saturated mixtures are derived.Consequently,the stress-strain relation under triaxial stresses is derived.By comparing the stress-strain curves of coal containing different gas components,the effect of adsorption on the constitutive relation of gas-filled coal is analyzed.Meanwhile,the theoretical values from the proposed constitutive relation are compared with the experimental results.Results from the constitutive relation agree well with experimental curves.It is shown that the constitutive equations are able to describe the difference in deformation behavior with respect to gas adsorption,which is affected by the difference in gas adsorption and that the stress-strain relation,under the same porosity and pore pressure,even when the skeleton structure of the coal satisfies the Hooke＇s linear elastic constitutive relation.

关 键 词：采矿工程 含气煤 本构关系 吸附作用 混合物理论 体积分数 孔隙率 

分 类 号：TD712[矿业工程—矿井通风与安全]