Micromechanical Modeling of Fracture Energy for Hooked-End Steel Fiber-Reinforced Cementitious Composites
Micromechanical Modeling of Fracture Energy for Hooked-End Steel Fiber-Reinforced Cementitious Composites
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DOI：
10.1177/1056789510397072
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发表时间：
2012-04
影响因子：
4.2
通讯作者：
B. Xu;J. Ju;H. Shi
中科院分区：
文献类型：
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作者：
B. Xu;J. Ju;H. Shi
由于纤维与水泥基复合材料断裂面相交的拔出行为与单纤维拔出试验相似，在单纤维拔出试验的基础上，建立了钩状钢纤维增强水泥基复合材料（HSFRCC）断裂能的细观力学模型。与断裂面相交的钢纤维弯钩端有各种变形，一般可分为弯钩端完全变形、弯钩端部分变形和弯钩端不变形。有变形的钩端的钢纤维的拔出能量显着不同，与未变形的一个;钩端变形和未变形的钩端的拔出能量的推导进行第一。采用概率方法建立了高强钢纤维碾压混凝土的断裂能模型，考虑了与断裂面相交的所有钢纤维的能量贡献。实验验证所提出的微观力学模型进行，并观察到良好的协议与单轴拉伸试验的实验数据进行比较。由于该断裂能模型是弯钩钢纤维和水泥基材料的物理和微观几何性质的函数，因此可用于指导高强钢纤维碾压混凝土的优化设计。
Since pullout behaviors of fibers intersecting a fracture plane of cementitious composite are similar to those in a single-fiber pullout test, micromechanical model of fracture energy for hooked-end steel fiber-reinforced cementitious composite (HSFRCC) is developed on the basis of single hooked-end steel fiber pullout test. The hooked-ends of steel fibers intersecting a fracture plane have various deformations which can be generally classified into hooked-end total deformation, partial deformation, and nondeformation. The pullout energy of steel fiber with deformed hooked-end is significantly different from that with nondeformed one; derivations of pullout energies of hooked-end steel fibers with deformed/nondeformed hooked-ends are carried out first. The fracture energy model of HSFRCC is proposed using probabilistic method accounting for energy contributions from all steel fibers intersecting the fracture plane. Experimental validation of the proposed micromechanical model is performed, and excellent agreements are observed in comparison with experimental data from uniaxial tensile tests. As the proposed fracture energy model is a function of physical and micro-geometric properties of hooked-end steel fibers and cementitious matrix, it can guide optimal design of HSFRCC.