摘要
为了研究岩石材料在"静态-准静态-动态"范围内压缩特性的率效应,同时也为了克服现有静态和动态加载方法中试样尺寸存在差异的不足,在综合分析静力试验消除端部效应和动力试验试样受力平衡的基础上,统一采用φ25 mm×50 mm的圆柱形细花岗岩试样,分别利用INSTRON液压伺服试验机和SHPB冲击试验机,进行"静态-准静态-动态"范围内的压缩试验,获得压缩强度、峰值应变和切线模量随加载率(应变率)增加的变化规律。利用获得的实验数据也研究了应变率与加载率之间的关系,结果表明两者(分别取对数)之间存在很好的线性函数关系。为了描述岩石材料从低到高加载率(应变率)范围内的率效应,提出一种基于率效应的动态增强因子统一模型,之后分别以应变率和加载率作为基本参数,考察该模型对压缩强度、切线模量和峰值应变的适用性。研究结果表明,基于加载率效应的动态增强因子模型可以很好地描述压缩强度和切线模量的率效应规律。
In order to investigate the rate effect of rock material in the loading range of ＂ static-quasi static-dynamic＂and to overcome the shortcomings of the size effect in static loading and dynamic loading methods,on the basis of comprehensive analysis in eliminating the end effect in static test and achieving the force balance for dynamic test specimen,a cylindrical fine granite specimen with φ 25 mm×50 mm was adopted. The compression tests were carried out in the range of static-quasi-static-dynamic by using the hydraulic servo tester INSTRON and SHPB（split Hopkinson pressure bar） device respectively. The variations of compressive strength,peak strain and tangent modulus with strain rate（loading rate） were obtained. The relationship between the strain rate and the loading rate was also investigated using the obtained experimental data,and the results show that there is a good linear relationship between them（taking logarithm respectively）. In order to describe the rate effect of rock material from low to high loading rate（or strain rate）,a new model of dynamic increase factor（DIF） based on rate effect was proposed,and the applicability of the model to the compressive strength,tangent modulus and peak strain were investigated by using the strain rate and loading rate as the basic parameters respectively. The results show that the new model of DIF based on the loading rate effect can describe well the rate effect of compressive strength and tangent modulus.
作者
宫凤强
王进
李夕兵
GONG Fengqiang;WANG Jin;LI Xibing(School of Resources and Safety Engineering,Central South University,Changsha,Hunan 410083,China;Advanced Research Center of CSU,Central South University,Changsha,Hunan 410083,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2018年第7期1586-1595,共10页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(41472269)~~
关键词
岩石力学
率效应
动态增强因子
加载率
应变率
抗压强度
rock mechanics
rate effect
dynamic increase factor（D/F）
loading rate
strain rate
compressive strength
