钢纤维对双丝拉拔试件动态破裂性能的影响

1)广州大学土木工程学院,广东广州 510006; 2)深圳市市政设计研究院有限公司,广东深圳 518029

混凝土; 钢纤维; 双丝拉拔; 声发射; 动态破坏过程; 微裂纹

Influence of steel fiber on dynamic failure property of twin fibers pull-out specimens
ZHANG Yafang1, GUO Zhongxiang1, LIU Hao1, 2, HE Juan1, and LU Juan1

1)School of Civil Engineering, Guangzhou University, Guangzhou 510006, Guangdong Province, P.R.China2)Shenzhen Municipal Design & Research Institute Co. Ltd., Shenzhen 518029, Guangdong Province, P.R.China

concrete; steel fiber; twin fibers pull-out; acoustic emission; dynamic damage process; micro-crack

DOI: 10.3724/SP.J.1249.2021.02136

备注

采用RFPA2D-dynamics软件,考虑各相材料的细观非均匀分布,建立双丝拉拔动态数值模型,研究动荷载作用下钢纤维体积分数变化对双丝拉拔试件力学性能的影响. 从细观单元的弹性损伤本构关系出发,分析不同钢纤维体积分数试件从微裂纹萌生、扩展直至贯通的动态拉拔破坏过程,得到不同钢纤维体积分数试件的荷载-位移曲线和声发射累积能量曲线. 结果表明,在动载作用下,钢纤维体积分数变化对试件破坏模式影响较大. 随着钢纤维体积分数的增加,试件的耗能水平先增加后降低. 钢纤维体积分数为1.6%时,试件的耗能水平最高,是素混凝土试件的1.36倍.

By using the realistic failure process analysis RFPA2D-dynamics software, we establish a dynamic numerical model for twin fibers pull-out test. The microscopic non-uniformity of mechanical properties of concrete materials in different phases is accepted to study the influence of steel fiber volume content under dynamic load on mechanical properties. According to the elastic damage constitutive relationship of the meso-element, the dynamic tensile failure process of specimens with various steel fiber volume content, from micro-cracks initiation, propagation to crack penetration, is studied in details. Furthermore, curves of load-displacement and acoustic emission cumulative energy could also be obtained. The results show that variation of steel fiber volume content has significant influence on the failure pattern of the specimen under dynamic load. With the increase of steel fiber volume fraction, the energy consumption level of specimens first increases and then decreases. When the steel fiber volume fraction is 1.6%, the energy consumption reaches the highest, which is about 1.36 times of that of the plain concrete specimens.

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