摘要
为了考察裂缝长度对试件动态断裂韧度测试值的影响,采用圆盘直径为80mm变化裂缝长度的大理岩中心圆孔裂缝平台巴西圆盘试件,在霍普金森压杆系统上进行动态冲击劈裂试验。对不同裂缝长度试件动态试验时弹性压杆上测得的应变波形以及试件的断裂模式进行分析,用试验–数值的方法确定大理岩的动态断裂韧度。结果表明,在平均加载率为2.96×104MPa·m1/2·s-1的条件下,大理岩动态断裂韧度均值是其静态断裂韧度均值的2.6倍,随着裂缝长度的增加,动态测试值没有静态测试值的变化显著,最后对与试件尺寸和构形无关的动态断裂韧度的确定方法进行讨论。
In order to study the influence of crack length on test values of rock fracture toughness, one-size holed-cracked flattened Brazilian disc of marble specimen with diameter of 80 mm and specimens of different cracks lengths were performed with split Hopkinson pressure bar system. The strain waves in elastic bar and fracture mode of specimens with different crack lengths were obtained; and the dynamic fracture toughness of marble were determined by experiment-numerical analysis. It is shown that the average dynamic fracture toughness is 2.6 times larger than the average static one under average loading rate of 2.96×10^4MPa·m^1/2·s^-1; and the dynamic fracture toughness test values do not vary with crack lengths significantly compared to the static one. Moreover, the method to determine dynamic fracture toughness independent of size and configuration is discussed.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2009年第8期1691-1696,共6页
Chinese Journal of Rock Mechanics and Engineering
