Structural Hierarchy and Dynamic Size Effect of Rock Strength

摘要：

　　The mechanism of dynamic size effect of strength of rock is studied from the viewpoint ofstructural hierarchy.Relaxation model of Maxwell type for rock is used to obtain the relationship betweenstrength,sample size and strain rate.It is shown that because of the finiteness of crack propagation velocity,when the strain rate is well above certain characteristic strain rate,dynamic loading process takespredominant role,the stresses in sample have not enough time to relax,the larger the sample size is,themore time is needed for cracks in sample to go through the sample,the ultimate applied stresses beforemacrofracture are greater and the strength is higher.From other hand because of the size effect the higherdynamically applied stresses will activate the cracking at smaller scale levels of rock sample,and thefragment size is smaller.Based on the presented model the characteristic strain rate separating thepredominant diapasons for static and dynamic size effect is determined,and the fragment size is predictedsatisfactorily.

关键词： rock structural hierarchy dynamic size effect static size effect

作者: Chengzhi Qi Qihu Qian Qingming Li Mingyang Wang

作者单位: Beijing Higher Institution Research Center of Engineering Structures and New Materials,Beijing Unive Civil Engineering Institute,PLA University of Science and Technology,Nanjing 210007,China School of Mechanical,Aerospace and Civil Engineering,The University of Manchester,PO Box88,Mancheste

会议类型: 国际会议

会议名称: 第13届国际断裂大会(ICF2013)

会议地点: 北京

会议语种:英文

页码: 1-10

在线出版日期: 2013-06-16（万方平台首次上网日期，不代表论文的发表时间）