不同钢纤维掺量全轻混凝土梁落锤冲击试验研究  

Research on drop hammer impact test of all⁃lightweight concrete beams with different steel fiber contents

作　　者：杨艳敏[1] 葛泽森 YANG Yanmin;GE Zesen(School of Civil Engineering,Jilin Jianzhu University,Changchun 130118,China)

机构地区：[1]吉林建筑大学土木工程学院,长春130118

出　　处：《建筑结构》2024年第3期59-64,共6页Building Structure

基　　金：吉林省科技厅重点研发项目(20200403071SF);国家应急管理部安全事故防治科技项目(jilin-0001-2018AQ);吉林省教育厅“十三五”科学技术项目(JJKH20200281KJ)。

摘　　要：由于全轻混凝土结构抗剪承载力较低,因此有必要探究钢纤维的加入对全轻混凝土梁动力性能的影响。设计钢纤维体积掺量为0%、1%、2%共3根适筋梁,对其跨中区域进行落锤冲击试验,并利用LS-dyna有限元软件进行数值模拟,对比分析各试件破坏形态、冲击力时程曲线、跨中位移时程曲线。试验结果表明:在相同冲击荷载作用下随着钢纤维体积掺量的增加抑制裂缝产生和发展的现象越显著,并且裂缝相对更加集中于梁跨中区域,支座处裂缝相对减少。钢纤维的加入不影响试件冲击力最大值,但随着钢纤维体积掺量的增加,各试件冲击力第二峰值与最大值之比增加14%和26%,跨中位移最大值与残余位移分别降低3、8mm与3、7mm。经研究得出钢纤维的加入显著提高全轻混凝土梁抗冲击性能。Due to the low shear capacity of all⁃lightweight concrete structures,it is necessary to explore the influence of steel fiber on the dynamic performance of all⁃lightweight concrete beams.A total of three beams with steel fiber volume content of 0%,1%and 2%were designed,and the drop hammer impact test was carried out on the mid⁃span region.And using LS⁃dyna finite element software for numerical simulation.The failure modes,impact force time history curves and mid⁃span displacement time history curves of each specimen were compared and analyzed.The test results show that under the same impact load,with the increase of the volume fraction of steel fiber,the phenomenon of inhibiting the generation and development of cracks is more significant,and the cracks are relatively more concentrated in the middle area of the beam span,and the cracks at the support are relatively reduced.The addition of steel fiber does not affect the maximum impact force of the specimen,but with the increase of the volume content of steel fiber,the ratio of the second peak to the maximum impact force of each specimen increases by 14%and 26%,and the maximum mid⁃span displacement and residual displacement decrease by 3 mm and 8 mm,and 3 mm and 7 mm,respectively.The experimental study shows that the addition of steel fiber significantly improves the impact resistance of all⁃lightweight concrete beams.

关 键 词：钢纤维掺量 全轻混凝土梁 落锤冲击试验 抗冲击性能 破坏形态 

分 类 号：TU375.1[建筑科学—结构工程]