纤维增强混凝土剪力墙压弯剪耦合作用变形能力分析

Nonlinear analysis of axial-flexure-shear coupling behavior of fiber reinforced concrete shear walls

采用具有受拉应变硬化性能的新型纤维增强混凝土(FRC)能改善受力钢筋的变形能力,对提高剪力墙抗震性能有显著作用。为了建立更为合理的FRC剪力墙试件荷载-变形能力分析方法,用以分析平面复杂应力状态下,轴力、弯矩和剪力之间的相互作用机理,基于单轴弯剪模型,提出一个修正的纤维模型,其模拟结果与试验结果吻合较好。研究表明,建议模型能较为准确地预测单调荷载作用下纤维增强混凝土剪力墙的变形能力,其显著特点为变形分量计算明确,耦合作用机理清晰;并且可通过受压软化系数,较为直观地反映出混凝土性能差别对墙体变形能力的影响,同时展示出FRC优良的受剪和受压性能。

Since it is significant to improve inelastic deformation capacity of flexural steel reinforcement and enhance seismic behavior of shear wall by using fiber reinforced concrete( FRC) with tensile-hardening behavior,an effective approach is expected for the monotonic load-deformation response analysis of FRC shear walls considering axial-flexureshear coupling effect. Based on the uniaxial shear-flexure model( USFM),a modified fiber model is presented and verified with good agreements between the analytical and experimental results. Study results indicate that the proposed model can predict deformation capacity of FRC shear wall accurately and determine each displacement components clearly,considering coupling shear and flexure mechanisms. Effect of the material property difference of various concrete on seismic behavior of shear wall is simulated and reflected by the compression softening factor. And the high performance of FRC strain-hardening behavior on both shear and compression resistance capacity is shown with visualized physical conception as well.