摘要
为了探明活性粉末混凝土的疲劳损伤机理,建立疲劳损伤模型,对活性粉末混凝土棱柱体试件施加轴向等幅脉动荷载,观测4种不同应力水平下试件的破坏模式和宏观裂纹的演变过程,测量了加载过程中的纵向应变.研究表明,活性粉末混凝土的疲劳损伤可分为内部损伤成核、损伤稳定发展和损伤失稳发展3个阶段,且只有当荷载循环次数超过一定阈值时才会发生宏观疲劳损伤.文中还采用累积残余塑性应变定义了活性粉末混凝土的损伤,根据试验数据得到了疲劳损伤曲线;利用损伤力学理论建立了活性粉末混凝土的疲劳损伤演化模型,确定了模型参数,模型表达合理,形式简单,便于工程应用.
In order to reveal the fatigue damage mechanism and to establish a fatigue damage model of reactive powder concrete, axial equiamplitute pulsating loads are imposed to reactive powder concrete prism specimens, and the failure pattern and macro-crack evolution of the specimens at four different stress levels are observed. Then, the development of longitudinal strain with the loading is measured. The results show that the fatigue damage of reactive powder concrete develops from a nucleation stage to a stable stage and further to an instability stage, and that there is no macro-damage till the cyclic number of load exceeds a threshold. Moreover, a damage variable is defined according to the cumulative residual plastic strain, and some fatigue damage curves are plotted according to the experimental data. Finally, based on the theory of damage mechanics, a fatigue damage model of reactive powder concrete with simplicity and rationality is established for engineering application, with its parameters being also determined.
出处
《华南理工大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2009年第3期114-119,共6页
Journal of South China University of Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(50778021)
关键词
活性粉末混凝土
累积残余应变
疲劳损伤
reactive powder concrete
cumulative residual strain
fatigue damage
