摘要
以LC30全轻页岩陶粒混凝土为基准,对聚丙烯纤维、钢纤维和多壁碳纳米管不同组合掺入方式,分别进行了静力和分离式Hopkinson压杆(SHPB)冲击试验,利用HJC模型和LS-DYNA软件对素混凝土和钢纤维混凝土的动态应力-应变曲线进行了数值模拟。结果表明:全轻纤维混凝土不仅具有应变率效应和临界值,而且还具有强度效应和能量效应;并随应变率提高,其动态峰值应力和峰值应变、总能耗随之增大,且动态应力增长系数与应变率的对数具有显著相关性,但纤维掺入方式具有明显的差异性。其中,单掺时以聚丙烯纤维为最好,双掺时差异不大,三掺时为最好。数值模拟与试验曲线相近,但峰值应力较大和下降段差异较大,表明HJC模型对全轻混凝土及其纤维混凝土具有一定的局限性。
Taking LC30 all-lightweight shale ceramsite concrete(ALWSCC)as a comparison criterion,static and SHPB tests were conducted on different kinds of fiber reinforced all-lightweight concrete(FRALWC),such as polypropylene fiber reinforced all-lightweight concrete(PFRALWC),steel fiber reinforced all-lightweight concrete(SFRALWC),multi-wall carbon nanotube fiber reinforced all-lightweight concrete(MCNFRALWC),and composite fiber reinforced all-lightweight concrete(CFRALWC).Then the LS-DYNA software was used to simulate the dynamic impact responses of plain concrete and SFALWC based on the modified HJC constitutive model.The results show that ALWC not only has the strain rate effect and the corresponding critical value,but also has the strength effect and energy effect.With the increase of strain rate,the dynamic peak stress,peak strain and total energy consumption increase.The dynamic stress growth coefficient has a significant correlation with the logarithm of strain rate.The mechanical properties of FRALWC are of different kinds and PFRALWC displays the best among all the FRALWC.The more the number of fiber types participated in,the better the mechanical properties of CFRALWC.The results of numerical simulations are similar to those of the experiments,but the peak stress of specimens and the falling segment of stress-strain curves are quite different,which shows that the applicability of HJC constitutive model has certain limitation for ALWC and FRALWC.
作者
杨健辉
李潇雅
叶亚齐
王新宇
YANG Jianhui;LI Xiaoya;YE Yaqi;WANG Xinyu(Henan Province Engineering Laboratory for Eco-architecture and the Built Environment,Henan Polytechnic University,Jiaozuo 454000,China;School of Civil Engineering,Henan Polytechnic University,Jiaozuo 454000,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2020年第2期148-153,177,共7页
Journal of Vibration and Shock
基金
国家自然科学基金(41172317)
作者简介
第一作者:杨健辉,男,博士后,教授,1969年生。
