超高性能混凝土无腹筋梁剪切失效有限元模拟  

Finite element modelling of shear failure of UHPC beams without stirrups

作　　者：张世顺[1] 曾卓 陈东[1] 田径 聂雪飞 ZHANG Shishun;ZENG Zhuo;CHEN Dong;TIAN Jing;NIE Xuefei(School of Civil and Hydraulic Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;CCCC Second Harbor Engineering Company Ltd.Design&Research Institution,Wuhan 430056,China)

机构地区：[1]华中科技大学土木与水利工程学院,湖北武汉430074 [2]中交第二航务工程局有限公司设计研究院,湖北武汉430056

出　　处：《建筑结构学报》2023年第1期300-309,共10页Journal of Building Structures

基　　金：国家自然科学基金项目(52078231)。

摘　　要：为了研究超高性能混凝土(UHPC)无腹筋梁的剪切失效机理,采用有限元软件ABAQUS对UHPC无腹筋梁的受剪性能进行了三维精细有限元模拟。模型中考虑了材料非线性和几何非线性,对于UHPC材料受拉性能的模拟考虑其应变硬化的性能。结果表明:由模拟得到的UHPC无腹筋梁的荷载-跨中挠度曲线和破坏模态等均与试验结果吻合良好,UHPC无腹筋梁的剪切破坏可分为线弹性阶段、微裂缝开展阶段、宏观多裂缝开展阶段、破坏阶段和残余强度阶段等五个阶段;UHPC无腹筋梁的受剪承载力受UHPC抗拉强度的影响最大,其随着UHPC抗拉强度的提升呈线性增长;UHPC的断裂能大小和受拉应变硬化长度主要影响梁的延性,对梁的受剪承载力影响不大;UHPC的抗压强度则对梁的受剪承载力和延性均影响较小;随着预应力的提高,梁的延性不断降低,受剪承载力则先上升后下降;随着剪跨比的增大,梁的刚度和受剪承载力均逐渐减小。In order to study the shear failure mechanism of ultra high performance concrete(UHPC) beams without stirrups, the finite element(FE) software ABAQUS was used to establish a three-dimensional fine FE model simulating the shear behavior of UHPC beams without stirrups. Material nonlinearity and geometric nonlinearity were both carefully considered in the model, and the strain hardening behavior of UHPC was considered in its tensile constitutive model. The predicted load-midspan deflection curves and failure modes of the beams from the FE model are in good agreement with the experimental results. The FE results showed that the shear failure of a typical UHPC beam without stirrups can be divided into five stages: linear elastic stage, micro-crack developing stage, multiple cracking stage, failure stage, and residual strength stage. The verified FE model was then used to analyze the shear behavior of the UHPC beams without stirrups through parametric studies. The results showed that the tensile strength of UHPC has the greatest impact on the shear capacity of the beam, and the shear capacity of the beam increases almost linearly with the increase of the tensile strength of UHPC;the fracture energy and the tensile strain hardening length of UHPC mainly affect the ductility of the beam and have little effect on its shear capacity;the compressive strength of UHPC has an insignificant effect on the shear capacity and ductility of the beam;with the increase of the prestress level, the ductility of the beam continuously decreases, and the shear capacity of the beam first increases and then decreases;as the shear-span ratio of the beam increases, both the stiffness and shear capacity of the beam decrease.

关 键 词：无腹筋梁 超高性能混凝土 有限元模拟 参数分析 剪切性能 

分 类 号：TU375.1[建筑科学—结构工程] TU311.41