考虑端面摩擦效应的煤样统计损伤尺度本构模型  

SCALE CONSTITUTIVE MODEL OF STATISTICAL DAMAGE FOR COAL SAMPLES WITH EFFECT OF INTERFACIAL FRICTION

作　　者：宋良[1,2] 刘卫群[1,2] 靳翠军 

机构地区：[1]中国矿业大学力学与建筑工程学院,江苏徐州221116 [2]深部岩土力学与地下工程国家重点实验室,江苏徐州221008 [3]徐州工程机械集团,江苏徐州221004

出　　处：《工程力学》2012年第11期344-349,共6页Engineering Mechanics

基　　金：国家自然科学基金项目(50774083;41074040);教育部"新世纪优秀人才支持计划"课题项目(NCET-07-0803);国家"973计划"子课题项目(2009CB219605)

摘　　要：煤与其它岩石类材料一样,在力学特性等方面具有尺度效应,基于Weibull理论和脆性材料强度的随机分布假设,采用损伤力学的方法建立了考虑端面摩擦效应的煤样单轴压缩尺度本构模型,并结合试验对模型进行了分析和验证。结果表明,煤样抗压强度随高宽比的增加明显减小,端面摩擦效应是导致Weibull理论与试验结果产生较大差异的主要原因,修正之后的本构关系与试验结果具有较好的相符性,其不仅能很好地反映煤样单轴压缩强度随尺寸的变化规律,而且能更好的描述单轴压缩的整个加载过程。Coal has also scale-dependent mechanical properties like many other rock materials. Based on the Weibull theory and the assumption that strength is randomly distributed for brittle materials, a scale constitutive model in uniaxial compression for coal samples with the effect of interfacial friction is developed according to the theory of damage mechanics, and then the model is verified by uniaxial compressive experiments. Results show that the ultimate compression strength of coal samples obviously decreases as the aspect ratio increases, and the interfacial friction becomes the main reason for the differences of the results between Weibull theory and experiments. While the results obtained from the modified model agree better with experiments ones, it can reflect the law of changeable uniaxial compressive strength with the coal sample size and describe almost the whole process of uniaxial loading.

关 键 词：尺度效应 本构关系 单轴压缩 煤样 端面摩擦 

分 类 号：TD313[矿业工程—矿井建设]