标定ISRM岩石断裂韧度新型试样CCNBD的应力强度因子

CALIBRATION OF STRESS INTENSITY FACTOR FOR NEW TYPE OF FRACTURE TOUGHNESS SPECIMEN CCNBD SUGGESTED BY ISRM

国际岩石力学学会(International Society for Rock Mechanics——ISRM)在1995年提出一种新型的岩石断裂韧度试样——人字型切槽巴西圆盘试样(cracked chevron notched Brazilian disc —— CCNBD)。但是,该试样的重要力学参数即无量纲应力强度因子的标定尚有问题。针对此关键问题进行深入的研究,获得了该试样新的更准确的标定值。采用大型商业有限元软件ANSYS,引入了ANSYS子模型法和局部裂纹子模型法进行三维应力强度因子的计算。结果表明,子模型方法具有很高的精度和适用性。在计算了CCNBD试样的无量纲应力强度因子以后,还综合比较了前人相关的一些结果,从理论分析的角度证明了所得结果是合理可靠的。

International Society for Rock Mechanics (ISRM) proposed a new type of rock fracture toughness specimen-cracked chevron notched Brazilian disk (CCNBD) in 1995. However, the calibration of the dimensionless stress intensity factor, which is an important mechanical parameter, is still in question. To solve this problem, the in-depth research has been carried out, and the new and more accurate value for the calibration is obtained. After calculation of the dimensionless stress intensity factor of the CCNBD specimen, comprehensive comparison with previous reference values is performed. The result proves theoretically to be reasonable and reliable.