复合材料科学与工程 ›› 2023, Vol. 0 ›› Issue (7): 98-105.DOI: 10.19936/j.cnki.2096-8000.20230728.014

• 应用研究 • 上一篇    下一篇

初始应力损伤碳纤维高强混凝土动态力学性能研究

郝丽1, 张凯2, 吴文飞3   

  1. 1.包头铁道职业技术学院, 包头 014060;
    2.太原理工大学 木建筑工程学院, 太原 030024;
    3.中国建筑一局集团有限公司西北分公司, 西安 710000
  • 收稿日期:2022-06-27 出版日期:2023-07-28 发布日期:2023-08-22
  • 作者简介:郝丽(1987—),女,硕士,讲师,主要从事混凝土性能、建筑构件力学性能方面的研究,HaoLi20220619@163.com。
  • 基金资助:
    国家自然科学基金(51978437)

Study on dynamic mechanical properties of carbon fiber reinforced high strength concrete with initial stress damage

HAO Li1, ZHANG Kai2, WU Wenfei3   

  1. 1. Baotou Railway Vocational and Technical College, Baotou 014060, China;
    2. College of Architecture and Civil Engineering, Taiyuan University of Technology, Taiyuan 030024, China;
    3. Northwest Branch of China Construction First Bureau Group Co., Ltd, Xi’an 710000, China
  • Received:2022-06-27 Online:2023-07-28 Published:2023-08-22

摘要: 为探究初始应力损伤下碳纤维高强混凝土试件在冲击荷载作用下的力学性能变化规律,采用声波检测仪测量不同应力幅值(0σm、0.3σm、0.4σm、0.5σm、0.6σm、0.7σm,σm为试件的单轴抗压强度)损伤下碳纤维高强混凝土纵波波速及损伤因子,利用电液伺服压力机及分离式霍普金森压杆(SHPB)对损伤试件开展不同应变率下的单轴压缩试验,分析试件峰值应力、动态增强因子(DIF)、能量耗散与应变率及试件损伤程度间的关系。结果表明:循环荷载损伤下试件纵波波速降低,且损伤应力幅值越大,试件纵波波速降幅越大,损伤因子增幅增加,损伤因子与应力幅值间呈二次函数正相关;0.2 MPa气压下0.3σm、0.4σm、0.5σm、0.6σm、0.7σm损伤应力作用下试件峰值应力降幅分别为5.86%、16.45%、23.97%、36.10%、52.29%,降幅不断增大,损伤试件承载能力随之降低,且损伤应力幅值越大,试件损伤程度越高,峰值应力及DIF越小;动载作用下试件入射能、反射能、透射能及耗散能均随时间的增加而增大并最终趋于定值;随着损伤应力幅值的增大,试件反射能不断增大,透射能及耗散能逐渐减小,应力损伤作用会降低试件的能量耗散密度,且损伤应力幅值越大,试件吸能效果越低。

关键词: 冲击荷载, 应力损伤, 碳纤维高强混凝土, 损伤因子, 峰值应力, 能量耗散, 复合材料

Abstract: In order to explore the change law of mechanical properties of carbon fiber reinforced high strength concrete specimens under impact load under initial stress damage, the longitudinal wave velocity and damage factor of carbon fiber reinforced high strength concrete under different stress amplitude (0σm, 0.3σm, 0.4σm, 0.5σm, 0.6σm, 0.7σm, σm is the uniaxial compressive strength of the specimen) damage were measured by acoustic detector. Uniaxial impact compression tests of damaged specimens under different strain rates were carried out by electro-hydraulic servo press and split Hopkinson pressure bar (SHPB). The relationships among peak stress, dynamic enhancement factor (DIF), energy dissipation, strain rate and damage degree of specimens are analyzed. The results show that the longitudinal wave velocity of the specimen decreases under cyclic load damage. And the larger the damage stress amplitude is, the larger the longitudinal wave velocity drop of the specimen is, and the increase of the damage factor is increased. There is a quadratic positive correlation between damage factor and stress amplitude. The peak stress decreases by 5.86%, 16.45%, 23.97%, 36.10% and 52.29% respectively under 0.3σm, 0.4σm, 0.5σm, 0.6σm, 0.7σm damage stress at 0.2 MPa air pressure. The decreasing amplitude keeps increasing, the bearing capacity of the damaged specimen decreases, and the larger the damage stress amplitude is, the higher the damage degree of the specimen is, and the smaller the peak stress and DIF are. Under the action of dynamic load, the incident energy, reflected energy, transmitted energy and dissipated energy of the specimen all increase with the increase of time and finally tend to constant values. With the increase of damage stress amplitude, the reflected energy of the specimen increases, while the transmitted energy and dissipation energy decrease gradually. The effect of stress damage will reduce the energy dissipation density of the specimen, and the larger the damage stress amplitude, the lower the energy absorption effect of the specimen.

Key words: impact load, stress damage, carbon fiber high strength concrete, damage factor, peak stress, energy dissipation, composites

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