摘要
为确定适用于不同岩石材料的强度和模量在不同应变率下的统一动态增强因子模型,统计不同岩石材料强度和模量与应变率之间关系的大量试验数据,总结描述岩石材料强度和模量在不同应变率下的动态增强因子模型的基本类型,从标准差、拟合优度、试验规律和平滑度等方面综合评价最适用于反映不同岩石材料强度和模量的动态增强因子模型。结果表明,评价动态增强因子模型的适用性,不能只看标准差和拟合优度,还要与岩石强度和模量的率效应等试验规律以及平滑程度进行对比;中低应变率下岩石强度与应变率的对数符合线性正相关,而指数函数最适合反映中高应变率下不同岩石强度的率效应,同时,也确定目前为止较为适合描述全应变率下不同岩石强度的率效应统一模型;与强度率效应相比,不同应变率下的不同类型岩石模量率效应的动态增强因子模型与其基本相同,不同之处则是中低应变率下岩石模量与应变率对数的幂成线性正相关,而适合描述中高应变率下不同岩石模量率效应的模型除了指数函数,还有幂函数。
In order to determine the uniform dynamic increasing factor model for the strength and modulus of different rock materials at different strain rates,a large number of experimental data for the relationship between strength and modulus of different rock materials and strain rate are counted.The basic types of dynamic increasing factor models describing rock material strength and modulus at different strain rates are summarized.From the aspects of standard deviation,goodness of fit,experimental law and smoothness,a best suitable dynamic increasing factor model for reflecting the strength and modulus of different rock materials is comprehensively evaluated and then determined.The results show that the applicability of the evaluation of the dynamic increasing factor model can not only be determined by the standard deviation and the goodness of fit,but also by the experimental law and smoothness of rate effect of the rock strength and modulus.The rock strength and the logarithm of strain rate at medium and low strain rates is consistent with linear positive correlation.And the exponential function is most suitable for reflect the rate effect of different rock strength under medium and high strain rates.Further,the best uniform model for describing the strength of different rocks at full range strain rate is also determined.Compared with rate effect of the strength,the dynamic increasing factor model embodying rate effect of different types of rock modulus at different strain rates is almost the same.The difference is that the rock modulus at the medium and low strain rates is linearly positively correlated with the logarithm of the strain rate.Meanwhile,models suitable for describing the rate effect of different rock modulus at medium and high strain rates are not only exponential function but also power function.
作者
周永强
盛谦
李娜娜
付晓东
ZHOU Yongqiang;SHENG Qian;LI Nana;FU Xiaodong(State key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China;Wuhan Library,Chinese Academy of Sciences,Wuhan,Hubei 430071,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2020年第S02期3245-3259,共15页
Chinese Journal of Rock Mechanics and Engineering
基金
国家重点研发计划项目(2018YFC0809400)
国家自然科学基金资助项目(51809258,51679232)。
关键词
岩石力学
应变率
岩石材料
强度
模量
动态增强因子模型
适用性
rock mechanics
strain rate
rock material
strength
modulus
dynamic increasing factor model
applicability
