基于不同强度等级混凝土的动力学特性研究  

Study on dynamic characteristics of concrete based on different strength grades

作　　者：秦浩 刘磊[1] 安华明 曹俊阳 刘申张 候舜 QIN Hao;LIU Lei;AN Huaming;CAO Junyang;LIU Shenzhang;HOU Shun(Faculty of Land Resource Engineering,Kunming University of Science and Technology,Kunming Yunnan 650093,China;Faculty of Public Safety and Emergency Management,Kunming University of Science and Technology,Kunming Yunnan 650093,China;China Railway High-speed Railway Electrical Equipment Co.,Ltd.,Baoji Shaanxi 721006,China;Kunming Institute of Land and Resources Engineering,Kunming Yunnan 650093,China)

机构地区：[1]昆明理工大学国土资源工程学院,云南昆明650093 [2]昆明理工大学公共安全与应急管理学院,云南昆明650093 [3]中铁高铁电气装备股份有限公司,陕西宝鸡721006 [4]昆明国土资源工程学院,云南昆明650093

出　　处：《中国安全生产科学技术》2019年第12期115-121,共7页Journal of Safety Science and Technology

基　　金：国家自然科学基金项目(11862010)

摘　　要：基于TAW-2000D电液伺服岩石三轴仪和直径75 mm的霍普金森压杆试验装置,得到了C25,C35和C45混凝土在静、动载荷作用下的应力-应变曲线,探讨了混凝土强度等级、动态峰值强度、峰值应变和应变率之间的变化规律。结果表明:混凝土准静态应力-应变曲线和动态应力-应变曲线在形态上存在明显差异,动态应力-应变曲线的峰值点随应变率的增大向右上方移动,线弹性阶段各曲线斜率变化不明显;动态峰值应力、动态弹性模量和峰值应变均存在不同程度的率相关性,并且混凝土材料的应变率敏感性随其强度等级的提高而增强;混凝土C45的各力学指标对应变率的敏感性最强,C35次之,C25的应变率敏感性最弱;推导了应变率与强度等级和冲击速率之间的经验公式,三者之间存在非线性变化规律。Based on the TAW-2000D electro-hydraulic servo rock triaxial apparatus and the 75 mm diameter Hopkinson pressure bar test device,the stress-strain curves of C25,C35 and C45 concrete under the static and dynamic loads were obtained,and the change laws of concrete strength grade,dynamic peak strength,peak strain and strain rate were studied.The results showed that the quasi-static stress-strain curve and the dynamic stress-strain curve of concrete had obvious difference in morphology.The peak point of dynamic stress-strain curve moved towards the upper right with the increase of strain rate,and the slope change of each curve in the linear elastic stage was not obvious.All the dynamic peak stress,dynamic elastic modulus and peak strain had the rate dependence with different degrees,and the strain rate sensitivity of concrete material enhanced with the increase of its strength grade.It was found that each mechanical index of concrete C45 had the strongest sensitivity to the strain rate,followed by C35,and the strain rate sensitivity of C25 was the weakest.The empirical formula between the strain rate and the strength grade and impact velocity was derived,and there was a nonlinear variation law between them.

关 键 词：混凝土类材料 SHPB 强度等级 中高应变率 

分 类 号：X936[环境科学与工程—安全科学] TU528.1[建筑科学—建筑技术科学]