普通混凝土落锤冲击动态力学性能试验研究  

Experimental study on dynamic mechanical properties of ordinary concrete under drop hammer impact loading

作　　者：刘练 霍静思[1,2] 刘艳芝 王海涛[1] 谭清华[3] LIU Lian;HUO Jingsi;LIU Yanzhi;WANG Haitao;TAN Qinghua(China Ministry of Education Key Laboratory of Building Safety and Energy Efficiency,College of Civil Engineering,Hunan University,Changsha 410082,China;College of Civil Engineering,Huaqiao University,Xiamen 361021,China;College of Basic Education,National University of Defense Technology,Changsha 410072,Chin)

机构地区：[1]湖南大学土木工程学院教育部建筑安全与节能重点实验室,湖南长沙410082 [2]华侨大学土木工程学院,福建厦门361021 [3]国防科技大学指挥军官基础教育学院,湖南长沙410072

出　　处：《铁道科学与工程学报》2018年第6期1415-1423,共9页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51378200;51438010);教育部新世纪优秀人才计划资助项目(NCET-11-0123)

摘　　要：为研究普通混凝土材料的动态冲击力学性能,利用改进的落锤冲击试验装置,对C30混凝土圆柱体进行低速冲击试验。为降低落锤冲击惯性效应并获得稳定的加载速率,试验采用不同厚度的橡胶或海绵作为波形整形材料;采用20 mm厚橡胶时可消除惯性力影响,延长加载时间,使试件纵向应力趋于均匀分布,并实现恒定速率加载。试验结果表明:冲击荷载下混凝土破坏形态与静载下相同,动态增大系数(DIF)、极限应变与吸收能量随应变率增加而增加,在本文试验参数范围内应变率对混凝土应力-应变曲线形状影响较小。对已有混凝土动态力学性能试验结果进行统计和对比,验证了CEB2010规范公式偏于保守地描述了DIF与应变率的关系,且本文的研究结果填补了应变率10-1/s^100/s范围内试验数据。In order to investigate the dynamic behavior of ordinary concrete under impact loading, the low-speed impact tests on C30 concrete cylindrical specimens were carried out by using an improved drop hammer test setup. The rubber and sponge with different thickness were used as shaper to reduce the impact inertia effect and obtain steady loading rate. The 20 mm thick rubber pad significantly reduced the inertia effect and prolonged the loading time duration. The longitudinal stress of the specimens tended to uniformly distribute and led to a constant loading rate. The test results show that the concrete failure mode under impact loading is the same as that under static loading. Furthermore, dynamic increase factor（DIF）, ultimate strain and energy-absorption increase with the increase of strain rate. However, it is found that within the test parameters of this paper, the strain rate has little effect on the shape of stress-strain curves of concrete. Moreover, the dynamic tests on concrete from the literature were further summarized and compared. The formula recommended by CEB2010 can conservatively describe the relationship between DIF and strain rate. The results in this paper filled in the blank within the strain rate range of 10-1/s^100/s for the existing testing data.

关 键 词：落锤冲击 混凝土 波形整形 惯性力 动态增大系数 

分 类 号：TU528.1[建筑科学—建筑技术科学] TU502.6