Modeling of Constitutive Relationship of Fiber Reinforced Cementitious Materials

本研究建立了纤维增强水泥基材料在不同应力条件下的本构模型。对钢纤维混凝土的力学性能进行了试验研究，并根据试验结果建立了钢纤维混凝土的本构模型.单轴拉伸和剪切下的变形特性：峰值载荷和峰值位移受纤维形状的影响（即，锯齿直型、钩型和锚定型）。每根纤维的载荷-位移曲线可用多线性模型表示。通过叠加各纤维的行为并考虑纤维间的相互作用，建立了钢纤维混凝土的整体行为模型.重复加载下的变形特性：对于每种纤维类型，重复加载对载荷-位移曲线的影响是不同的。荷载-位移关系采用多线性模型表示.纤维嵌入长度对拔出性能的影响：峰值载荷和峰值处的位移与纤维嵌入长度呈双线性关系。埋置长度对荷载-位移曲线和声发射模式的影响取决于纤维的形状。

Modeling a constitutive relationship to express the behavior of fiber reinforced cementitious materials under various stress conditions was investigated in this research. The mechanical behavior of steel fiber reinforced concrete (SFRC) was experimentally studied and constitutive models were obtained based on the test results as summarized in the following.1. Deformational properties under uniaxial tension and shear :The peak load and the displacement at the peak are influenced by the fiber shape (i.e., indented straight type, hooked type and anchored type). The load-displacement curve of each fiber can be expressed by a multi-linear model. The overall behavior of SFRC is modeled by superimposing the behavior of each fiber and considering the interaction between fibers.2. Deformational properties under repeated loading :The effect of repeated loading on the load-displacement curve is different for each fiber type. The load-displacement relationship is expressed by a multi-linear model.3. Effect of fiber embedment length on the pullout properties :The peak load and the displacement at the peak are expressed by a bilinear model with respect to fiber embedment length. The effect of embedment length on the load-displacement curve and the AE event pattern depends on the fiber shape.