摘要
为了揭示钢筋的机械锚固与黏结锚固共同工作的机理,减小锚具大小和锚固长度,基于变形钢筋的黏结力主要来自机械咬合作用,提出一种肋尺度精细化建模方法.采用DIANA 10.4有限元(FE)软件分别对机械锚固、黏结锚固以及两者共同工作的3种钢筋拔出试验进行数值仿真分析.结果表明:弯钩基本属于黏结锚固机制,钢筋肋间混凝土齿键的剪切破坏导致黏结失效;机械锚固为局部承压机制,锚固板下混凝土处于三轴受压状态,局部压应力超过单轴抗压强度3倍以上.当机械锚固和黏结段共存时,由于钢筋和锚头的位置关系,锚固区将发生加载初期以黏结锚固为主到加载后期两者共同工作的应力重分布,荷载分担比例主要取决于黏结段长度和荷载水平.在无须假定黏结滑移关系的情况下,肋尺度模型能够较好地反映锚固钢筋的宏观力学响应和细观工作机理.
To reveal the combining mechanism of mechanical anchorage and bond,and to reduce the anchorage size and length,a refined rib-scale modeling approach was proposed based on the fact that the bond of deformed bars mainly comes from the mechanical interaction.Based on the finite element(FE)software DIANA 10.4,numerical simulations of three kinds of reinforcement pullout tests,where mechanical anchorage worked alone,bond worked alone and the two worked together,were carried out,respectively.Results show that the bond mechanism dominates the failure of hooked bar,which is caused by the shear failure of concrete keys between reinforcement ribs.The mechanical anchorage is controlled by local bearing mechanism,where the concrete beneath the anchor plate is under triaxial compression and the local compressive stress is more than three times of the uniaxial compressive strength.When mechanical anchorage and bond coexist,due to the position relationship between the reinforcement and anchor head,the bond plays a major role at the initial stage of loading,and with the increasing applied load,stress redistribution will occur in the anchorage zone where the mechanical anchorage and bond work together at the later stage.The load distribution ratio is mainly depended on the bond length and load level.Without assuming the bond-slip relationship,the macro-mechanical response and microscopic working mechanism of anchored bars can be well reflected by the rib-scale model.
作者
王玲茂
赵唯坚
WANG Ling-mao;ZHAO Wei-jian(College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,China;Center for Balance Architecture,Zhejiang University,Hangzhou 310028,China)
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2023年第8期1573-1584,共12页
Journal of Zhejiang University：Engineering Science
基金
国家自然科学基金资助项目(51879230)。
关键词
机械锚固
黏结
肋尺度精细化模型
有限元模拟
拔出试验
mechanical anchorage
bond
refined rib-scale model
finite element simulation
pullout test
作者简介
王玲茂(1998-),女,硕士生,从事装配式结构研究.orcid.org/0000-0002-8762-7193.E-mail:22012275@zju.edu.cn;通信联系人:赵唯坚,男,教授,博士.orcid.org/0000-0003-4227-5953.E-mail:zhaoweijian@zju.edu.cn。
