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力学与实践 ›› 2009, Vol. 31 ›› Issue (2): 40-45.doi: 10.6052/1000-0992-2007-382

• 应用研究 • 上一篇    下一篇

中心直裂纹平台巴西圆盘复合型动态应力强度因子

汪坤 冯峰 王启智   

  1. 四川大学土木工程及力学系
  • 收稿日期:2007-08-29 修回日期:1900-01-01 出版日期:2009-04-08 发布日期:2009-04-08

MIXED MODE DYNAMIC STRESS INTENSITY FACTORS OF CRACKED STRAIGHT THROUGH FLATTENED BRAZILIAN DISC SPECIMENS

  • Received:2007-08-29 Revised:1900-01-01 Online:2009-04-08 Published:2009-04-08

摘要: 为了指导用中心直裂纹平台巴西圆盘(CSTFBD)试样进行岩石复合型动态断裂 试验,利用有限元法首先验证了文献中对中心直裂纹巴西圆盘(CSTBD)得到的有关结果,分析 比较了不同无量纲裂纹长度(即裂纹半长和圆盘半径之比)时两种圆盘的I, II型动态应力 强度因子的时间历程,发现两者的差异大部分在10{\%}以内,同时验证了该文数值方法的可 靠性. 然后讨论了CSTFBD试样I, II型动态应力强度因子的复合比、起裂角以及纯II型加 载角. 研究成果可为复合型动态断裂试验中CSTFBD试样的加工、试样上应变片的粘贴、起裂 方向和起裂时间的估计等提供参考.

关键词: 复合型动态断裂, 中心直裂纹平台巴西圆盘, 动态应力强度因子, 加载角, 起裂角

Abstract: In order to establish a standard for the test of mixed mode dynamic fracture of rock with the cracked straight through flattened Brazilian disc (CSTFBD) specimen, we use finite element method first to check the related results in literature on the cracked straight through Brazilian disc specimen (CSTBD). The I-II mixed mode dynamic stress intensity factors (SIFs) of the two kinds of discs with different dimensionless crack lengths (i.e. the half length of the crack normalized by the radius of the specimen) are obtained to show that the differences of the dynamic SIF's time history between these two kinds of specimens are within 10{\%}, and the numerical method used in this paper is valid. Then for CSTFBD specimens, the I-II mixed ratio, the angle of crack initiation, and the loading angle for pure mode II fracture test are obtained. The results are useful for mixed mode dynamic fracture test of CSTFBD, including specimens preparation, the location and directional alignment of the strain gages, as well as the estimation for the crack initiation time and the crack initiation direction.

Key words: mixed mode dynamic fracture, cracked straight through