张亚芳,高 照,刘 浩,等.界面厚度对双丝拉拔混凝土力学性能的影响[J].深圳大学学报理工版,2017,34(No.5(441-550)):476-481.[doi:10.3724/SP.J.1249.2017.05476]
Zhang Yafang,Gao Zhao,Liu Hao,et al.Influence of interface thickness on twin fiber pull-out test of concrete[J].Journal of Shenzhen University Science and Engineering,2017,34(No.5(441-550)):476-481.[doi:10.3724/SP.J.1249.2017.05476]
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界面厚度对双丝拉拔混凝土力学性能的影响
张亚芳,高 照,刘 浩,何 娟

广州大学土木工程学院,广东广州 510006

混凝土; 细观力学; 双丝拉拔; 界面厚度; 声发射; 峰值荷载; 韧度

Influence of interface thickness on twin fiber pull-out test of concrete
Zhang Yafang, Gao Zhao, Liu Hao, and He Juan

Faculty of Civil Engineering, Guangzhou University, Guangzhou 510006, Guangdong Province, P.R.China

concrete; meso-mechanical; double fiber pull-out test; interface strength; acoustic emission; peak load; toughness

DOI: 10.3724/SP.J.1249.2017.05476

备注

考虑三维状态下界面、钢丝和混凝土基体三相材料物理力学参数的介观非均匀分布,利用有限元软件建立了双丝拉拔混凝土三维模型,研究了界面厚度对双丝拉拔混凝土力学性能的影响及界面的作用机理,获得试件声发射演化过程图和声发射-位移-荷载曲线,得到峰值荷载、韧性和声发射耗散总能量随界面厚度变化的曲线. 研究结果表明,试件的界面越厚,界面传递应力的能力越强,平均界面剪切强度越大,双丝发生脱黏的时间也越晚. 此外,适当增加界面的厚度有利于提高双丝试件的拉拔强度和韧性.

Meso-level heterogeneous distribution of interface mechanical parameters is investigated. Numerical models for twin fibers pull-out test are created by using 3D finite element method. Influence of interface thickness on damage pattern and mechanical properties is studied on twin fibers pull-out test specimens. By applying load with displacement control, load-displacement curves, acoustic emission(AE)accumulative curves and interface shear stress distribution curves of twin fibers and concrete matrix specimen are plotted. The damage pattern and AE pattern of pull-out test specimen vary along with the interface strength. The thicker the interface is, the higher the interface capacity for transferring stress and high shear strength. The splitting of fibers could happen later than the specimen with thin interface. In addition, appropriate thick interface benefits the improved peak load and toughness.

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