Drilling and blasting method is a common method of rock fragmentation in engineering. Meanwhile, the dynamic behaviours of rocks under blasting loads are different from those under impact loads. In this paper, a large-size arc-edge rectangle with edge notches (LAREN) specimen was posed to investigate the dynamic fracture parameters of brittle rock materials under blasting load. Three types of radial pre-cracks with different lengths were used, combining with the crack propagation gauge velocity test system, and the crack initiation time and propagation time were obtained, so as to obtain the crack propagation speed which is to be modified by the fractal theory. Also, the specimen rationality was analyzed by AUTODYN code in depth. At last, the dynamic stress intensity factors were estimated by using nonlinear finite element software ABAQUS and experimental results. It is concluded that the LAREN specimens can effectively lower the influence of the reflected tensile stress wave (by 54.18%) on the dynamic crack initiation and propagation, and have good applicability in the measurement of dynamic fracture parameters under blasting. With the development of pre-crack length, the crack time becomes longer, the average propagation speed becomes smaller, and the fluctuation of speed becomes smaller and tends to be stable. The increase of the pre-crack length also leads to the gradual decrease in the test value of the crack initiation toughness, while the test value of the propagation toughness is not constant.

钻爆法是工程中岩石破碎的常用方法。同时，岩石在爆炸载荷下的动力特性与冲击载荷下的动力特性不同。本文提出了一个大尺寸的带有边缘缺口的圆弧矩形试样（LAREN），以研究脆性岩石材料在爆炸荷载下的动态断裂参数。使用三种不同长度的径向预裂纹，结合裂纹扩展仪速度测试系统，获得了裂纹的萌生时间和扩展时间，从而求得裂纹的扩展速度。理论。此外，通过AUTODYN代码深入分析了样本合理性。最后，利用非线性有限元软件ABAQUS估算了动态应力强度因子，并进行了实验结果的估算。得出的结论是，LAREN试样可以有效地降低反射应力波（降低54.18％）对动态裂纹萌生和扩展的影响，并且在爆破中动态断裂参数的测量中具有良好的适用性。随着裂纹前长度的增加，裂纹时间变长，平均传播速度变小，速度的波动变小并且趋于稳定。裂纹前长度的增加还导致裂纹萌生韧性的测试值逐渐降低，而传播韧性的测试值不是恒定的。结论是，LAREN试样可以有效地降低反射应力波（降低54.18％）对动态裂纹萌生和扩展的影响，并且在爆破下动态断裂参数的测量中具有良好的适用性。随着裂纹前长度的增加，裂纹时间变长，平均传播速度变小，速度的波动变小并且趋于稳定。裂纹前长度的增加还导致裂纹萌生韧性的测试值逐渐降低，而传播韧性的测试值不是恒定的。结论是，LAREN试样可以有效地降低反射应力波（降低54.18％）对动态裂纹萌生和扩展的影响，并且在爆破下动态断裂参数的测量中具有良好的适用性。随着裂纹前长度的增加，裂纹时间变长，平均传播速度变小，速度的波动变小并且趋于稳定。裂纹前长度的增加还导致裂纹萌生韧性的测试值逐渐降低，而传播韧性的测试值不是恒定的。随着裂纹前长度的增加，裂纹时间变长，平均传播速度变小，速度的波动变小并且趋于稳定。裂纹前长度的增加还导致裂纹萌生韧性的测试值逐渐降低，而传播韧性的测试值不是恒定的。随着裂纹前长度的增加，裂纹时间变长，平均传播速度变小，速度的波动变小并且趋于稳定。预裂纹长度的增加还导致裂纹起始韧性的测试值逐渐降低，而扩展韧性的测试值不是恒定的。