超高性能混凝土剪力墙力学性能研究

Research on mechanical properties of ultra-high performance concrete material shear walls

超高性能混凝土(Ultra-High Performance Concretre,简称UHPC)因超高的耐久和耐磨、抗暴性能而被广泛运用于各类结构中。为了明确UHPC结构的力学性能及受力机理,对UHPC剪力墙的发展历史和研究现状进行综合整理,重点整理了现今超高性能混凝土剪力墙国内外研究的分析过程和结论成果。通过对不同试验荷载下的超高性能混凝土剪力墙的荷载位移曲线、滞回曲线、骨架线进行整理对比,整合相应抗剪承载力及整体试件荷载位移曲线公式。最后,通过二次开发定义了UHPC的受拉单轴本构,模拟UHPC剪力墙在单向水平荷载下的受力过程,提出了UHPC的骨架曲线,并拟合了卸载(再加载)的计算公式,可用于有限元计算中UHPC的基本本构方程。在此基础上,分析各参数对承载力的影响,并比较规范预测值与有限元计算值的差异,提出修正后的拉压杆模型对UHPC剪力墙的承载力进行预测。

Ultra-high Performance Concretre(UHPC) has wide application prospects in the field of the structure. In order to clarify the mechanical properties and stress mechanism of UHPC structure, this paper comprehensively sorts out the development history, research status and development prospects of UHPC shear wall, emphasizing on the analysis process and results of current domestic and international research on UHPC shear wall. Through sorting and comparing the load-displacement curve, hysteresis curve and frame line of UHPC shear wall under different experimental loads, the corresponding shear bearing capacity formula and the load-displacement curve formula of integral specimen are integrated. Finally, this paper establishes the finite element model of UHPC shear wall and defines the tension uniaxial constitutive force of UHPC through secondary development. On the basis of test data, the skeleton curves and hysteresis criteria of UHPC are proposed, and the formulae for the process of unloading(reloading) are fitted, which can be used for the basic constitutive model of UHPC in the numerical calculation. Through finite element simulation of its stress process under unidirectional horizontal load to analyze the influence of each parameter, and the code and simulated value are compared. A modified tension-compression model is put forward to predict the bearing capacity of UHPC shear wall.