断裂韧度试样CCNBD宽范围应力强度因子标定

国际岩石力学学会（ISRM）在1995年提出了一种新型岩石断裂韧度试样--人字形切槽巴西圆盘试样CCNBD，但是，其断裂韧度计算公式中的重要参数（即无量纲应力强度因子的标定）仍存在问题。采用一种新的分片合成方法并结合有限元法，参照ISRM给出的CCNBD试样的尺寸限制，对该范围试样的应力强度因子进行了宽范围的标定，以便在试验中能因地制宜地选用不同几何参数的CCNBD试样。结果表明：分片合成方法的计算值有很高的精度，不但减少了工作量，也使标定的无量纲应力强度因子比现有文献值更加准确、可靠。

Wide range calibration of the stress intensity factor for the fracture toughness specimen CCNBD

International Society for Rock Mechanics（ISRM）proposed in 1995 a new type of rock fracture toughness specimen—cracked chevron notched Brazilian disc（CCNBD），however，the calibration of the dimensionless stress intensity factor，which is an important mechanical parameter for fracture toughness calculation，is still in question. In order to provide the flexibility for choosing the CCNBD specimen geometrical parameters in experiments，considering the geometrical restrictions suggested by ISRM，the new and more accurate wide range calibration values are obtained by using a new slice synthesis method combined with finite element analysis. The results of the slice synthesis method are proved to be more accurate and reliable than those counterpart methods presently available in the reference.