摘要
对冻融前后的花岗斑岩进行相关静态、动态力学试验,获得试样不同冻融次数下的弹性模量、泊松比、单轴抗压强度、抗拉强度及冲击动载应力–应变曲线。在Holmquist-Johnson-Cook(HJC)模型参数分析的基础上,对经历不同冻融次数的花岗斑岩进行分离式Hopkinson压杆(SHPB)试验模拟。结合室内试验数据与数值模拟计算结果,分析花岗斑岩动载强度与应变率及冻融次数的关系。研究结果表明:试样冻融前后动态应力–应变曲线形态有所区别,SHPB试验的反射波和透射波形态发生明显变化,相同入射波情况下试样产生不同的应变率;SHPB试验数值模拟结果与实测值吻合较好,得到的不同冻融次数下花岗斑岩HJC模型参数是可靠的,数值模拟与室内试验相结合是研究分析的有效方法,二者优势互补;花岗斑岩动态强度受冻融次数与应变率共同影响,其影响效应相反,相互耦合。岩石冻融循环作用下的动载强度研究是一项重要课题,是冻融损伤条件下岩石动态本构关系研究的基础,对解决寒区露天边坡稳定性问题具有重要意义。
Elastic modulus,Poisson?s ratio,uniaxial compressive strength,tensile strength and dynamic stressstrain curves of granite porphyry were obtained under freezing-thawing cycles utilizing the relevant static and dynamic experiments. On the basis of parameter analysis to Holmquist-Johnson-Cook(HJC) model,numerical simulations of the split Hopkinson pressure bar(SHPB) tests were carried out utilizing the finite element software LS-DYNA. According to the results of numerical simulations and experiments,the relationships of the dynamic strength with the strain rate and the freezing-thawing cycles were obtained. The shapes of the stress-strain curves,the reflected and transmitted waves before and after freezing-thawing were different. Samples with the same incident wave under freezing-thawing cycles had the different strain rate. The numerical simulation on the basis of HJC model parameters agreed well with the results of SHPB experiment. The numerical simulation and the laboratory test complemented each other. The strain rate and the freezing-thawing cycles had opposite but interconnected effects on the dynamic strength.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2015年第7期1297-1306,共10页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(41272304
11472311)
关键词
岩石力学
冻融循环
数值模拟
HJC模型
动载强度
rock mechanics
freeze-thaw cycles
numerical simulation
HJC model
dynamic strength
