圆盘厚度对岩石抗拉强度公式的影响性研究  

Effect of Disc Thickness on Rock Tensile Strength Formula

作　　者：张盛[1] 梁亚磊[1] 李大伟[1] 

机构地区：[1]河南理工大学能源与工程学院,河南焦作454001

出　　处：《采矿与安全工程学报》2009年第4期450-454,共5页Journal of Mining & Safety Engineering

基　　金：河南省基础与前沿技术研究计划项目(072300440100);河南理工大学博士点基金项目(B2008-66648270)

摘　　要：为了考察平台巴西圆盘破坏的起裂点位置,保证其测试岩石抗拉强度的有效性,探讨了厚度对平台巴西圆盘测试抗拉强度的影响.基于Griffith强度准则,采用三维有限元软件,分析了不同厚度平台巴西圆盘中心轴线上等效应力σG的分布规律,并提出了2个能够消除厚度影响的平台巴西圆盘测试岩石抗拉强度的公式.结果表明,最先起裂位置发生在圆盘的端面中心点,而不是内部中心点,采用1倍直径厚度的试样时,圆盘端面中心点的等效应力σG是其内部中心点的1.62倍.如果使用常用公式确定岩石抗拉强度,建议采用小于0.3倍圆盘直径厚度的试样,其理论相对误差能控制在5.91%以下.In order to find out the location of initial fracture that leads to flattened Brazilian disc damage,to ensure its validity in testing rock tensile strength,the effect of thickness of Brazilian disc on testing tensile strength is discussed.Based on Griffith strength criterion,by 3-D finite element software,the equivalent stress σG distribution of the central axis is analyzed for flattened Brazilian discs different in thickness.Two formulas to determine the rock tensile strength by flattened Brazilian disc are put forward,which can eliminate the thickness effect.The results show that the initial fracture point occurres at the center point of the face plate,rather than the internal point.When a disc sample whose thickness is equal to the diameter is adopted,the equivalent stress σG at the center point of the face plate is 1.62 times greater than its internal center one.In determining the rock tensile strength according to the usual formula,it is recommended that the disc thickness is 0.3 times smaller than the disc diameter.By doing so,the theoretical relative error can be controlled to a value smaller than 5.91%.

关 键 词：抗拉强度 平台巴西圆盘 三维 厚度 有限元 

分 类 号：TD313.3[矿业工程—矿井建设]