纤维增强混凝土剪力墙恢复力模型试验与理论研究

Experimental and theoretical study of restoring force model of fiber reinforced concrete shear walls

以4个纤维增强混凝土剪力墙试件在低周往复水平荷载作用下的抗震性能试验为基础,考虑纤维增强混凝土的延性和应变硬化特性,分析纤维增强混凝土剪力墙的受力性能,推导整个受力过程不同阶段剪力墙顶点位移公式,建立剪力墙截面弯矩-曲率关系。通过与试验结果的比较,验证公式的合理性。在理论分析的基础上,以开裂点、屈服点、峰值点和极限点为特征点,并考虑刚度退化得出四线型荷载-位移恢复力模型,给出各特征点理论计算公式。利用此恢复力模型通过有限元软件ABAQUS建立纤维增强混凝土剪力墙非线性模型,模拟曲线与试验恢复力曲线较为吻合,表明提出的纤维增强混凝土剪力墙恢复力模型可为非线性分析提供依据。

Based on the seismic experiments of 4 Fiber Reinforced Concrete （FRC） shear walls under cyclic loading, the mechanical behaviors of FRC shear walls were investigated with the ductility and strain-hardening of FRC considered, the analytical formulae of top displacement at different stages of the entire loading process were derived, and the cross- section moment-curvature relationships of shear walls were established. Comparison between the calculated and the experimental results verifies the feasibility of the formulae. The restoring force model of FRC shear walls was established based on the theoretical analysis and experimental results, and a four-linear skeleton curve model considering stiffness degradation was proposed, by taking cracking point, yield point, peak point and ultimate point as feature points. The formulae of calculating these points are recommended through theoretical analysis. The nonlinear analysis, in which the four-linear skeleton curve model was taken into account, was performed to simulate the complete loading and mechanical behavior by using the finite element software ABAQUS. Consequently, the reliability of the finite element model was validated by the good agreement between analysis results and experimental results, providing the theoretical basis for nonlinear analysis.