华南理工大学学报(自然科学版) ›› 2025, Vol. 53 ›› Issue (12): 161-171.doi: 10.12141/j.issn.1000-565X.240560

• 材料科学与技术 • 上一篇    下一篇

单聚丙烯纤维拉拔界面变形的细观力学分析

毕玉洁1, 毛灵涛1,2, 刘海洲3, 刘娇娇1, 刘逸凡4   

  1. 1.中国矿业大学(北京) 力学与土木工程学院,北京 100083
    2.中国矿业大学(北京) 煤炭精细勘探与智能开发 全国重点实验室,北京 100083
    3.中国科学院深圳先进技术研究院,广东 深圳 518055
    4.中国建筑第七工程局有限公司,河南 郑州 450000
  • 收稿日期:2024-11-21 出版日期:2025-12-25 发布日期:2025-02-28
  • 通信作者: 毛灵涛(1974—),男,博士,教授,主要从事实验力学、图像处理与分析等研究。 E-mail:mlt@cumtb.edu.cn
  • 作者简介:毕玉洁(1986—),女,博士生,工程师,主要从事聚丙烯纤维混凝土细观力学性能研究。E-mail: 280833463@qq.com
  • 基金资助:
    国家重点研发计划项目(2022YFC2904102)

Microscopic Mechanical Analysis of Interface Deformation During Pull-Out of Single Polypropylene Fiber

BI Yujie1, MAO Lingtao1,2, LIU Haizhou3, LIU Jiaojiao1, LIU Yifan4   

  1. 1.School of Mechanics and Civil Engineering,China University of Mining and Technology,Beijing 100083,China
    2.State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources,China University of Mining and Technology,Beijing 100083,China
    3.Shenzhen Institutes of Advanced Technology,Chinese Academy of Sciences,Shenzhen 518055,Guangdong,China
    4.China Construction Seventh Engineering Division Corp. ,Ltd. ,Zhengzhou 450000,Henan,China
  • Received:2024-11-21 Online:2025-12-25 Published:2025-02-28
  • Contact: 毛灵涛(1974—),男,博士,教授,主要从事实验力学、图像处理与分析等研究。 E-mail:mlt@cumtb.edu.cn
  • About author:毕玉洁(1986—),女,博士生,工程师,主要从事聚丙烯纤维混凝土细观力学性能研究。E-mail: 280833463@qq.com
  • Supported by:
    the National Key Research and Development Program of China(2022YFC2904102)

摘要:

为研究聚丙烯纤维与混凝土界面的粘结力学特性,通过单纤维拉拔细观力学试验与数值模拟对界面的脱粘过程进行了分析。采用微CT与自行研制的单纤维拉拔装置建立了单纤维拉拔原位扫描观测系统,对压痕型单根聚丙烯纤维从砂浆基体中拔出的过程进行了原位扫描观测;结合力学正则化全局数字体图像相关法,获得了纤维与基体界面的变形场,由纤维与基体间共用节点的相对位移量化了界面的脱粘;基于CT图像建立了反映纤维和基体真实形状的三维细观数值模型,模拟分析了单纤维的拉拔过程。结果表明:拉力-位移曲线在峰值后呈现出与压痕纤维几何形状特点相关的多峰特征,由数字体图像相关法测量和数值模拟所得的界面应变场均呈现出与压痕纤维几何形状特点相关的应变集中现象,表明纤维的周期性压痕增强了拉拔过程中纤维与基体之间的摩擦和咬合力;界面处相对位移在纤维嵌入端部最大,沿纤维方向减小,在水平方向上,相对位移的变化规律与纤维的几何形状具有相关性;在垂直方向上,相对位移反映出拉力达到峰值荷载前纤维与基体已完全脱粘。

关键词: 聚丙烯纤维混凝土, 界面脱粘, 数字体图像相关法, 三维变形场测量

Abstract:

To investigate the bonding mechanical properties between polypropylene fiber and concrete interface, this study analyzed the debonding process of the interface through single fiber pull-out microscopic mechanical experiments and numerical simulations. An in-situ scanning observation system was established using micro CT and a self-developed single fiber drawing device to observe the process of pulling out a single polypropylene fiber with indentation from the mortar matrix. The deformation fields of the interface between fiber and matrix was obtained with mechanically regularized global digital volume correlation, and the interface debonding was quantified by calcula-ting the relative displacement of the shared nodes between the fiber and the matrix. A 3D microscopic numerical model reflecting the true shape of fibers and matrix was established based on CT images, and the single fiber dra-wing process was simulated and analyzed. The results show that the force-displacement curves display multi-peak fluctuations corresponding to the fiber geometry after the peak. The strain fields at interfaces measured by digital volume correlation and numerical simulation show a strain concentration phenomenon related to the geometric shape of the indentation fiber, indicating that the periodic indentation of the fiber increases mechanical interlocking and friction forces between the fiber and the matrix during pullout. The relative displacement at the interface is greatest and decreases along the fiber’s axial direction. In the horizontal direction, the variation of relative displacement was correlated with the geometric shape of the fiber. The relative displacement in the vertical direction reflected that the fiber and matrix have completely debonded before the pullout force reaches the peak load.

Key words: polypropylene fiber reinforced concrete, interface debonding, digital volume correlation method, measurement of three-dimensional deformation field

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