摘要
本文主要分析讨论了混凝土在等幅重复应力作用下的疲劳破损机理。试验分析表明,混凝土的疲劳损伤和疲劳变形的发展可以分为三个不同的阶段,占疲劳寿命大部分的第二阶段的应变发展几乎为线性变化,进入变形迅速发展的第三阶段时的混凝土纵向总变形与应力历史无关,是一个材料常数,可以作为判断混凝土发生疲劳破坏的准则。分别利用混凝土第一次加载时的最大应变与混凝土裂缝失稳扩展时的纵向总应变之比来表示所施加荷载的最大应力水平及混凝土应变发展第二阶段的应变增长速率,建立了二个估算混凝土等幅疲劳寿命的计算公式,计算结果与试验结果吻合较好。
This paper studied the fatigue damage mechanism of concrete under constant amplitude re-
peated loading. Analysis of the test results shows that the fatigue strain development and
the accumulation of the fatigue induced damage can be divided into three different stages. In
the second stage the development of fatigue strain is almost linear which occupies a great part
of the fatigue life.Test results show that the total longitudinal strain of concrete under re-
peated loading at the beginning of the third stage ε_(unstab) can be taken as a material parameter
only related to the property of concrete material. For the loading history affects a little on
the value of ε_(unstab), it can be used as a criterion for assessing the fatigue damage of con-
crete. Based on the above analysis, two formulas for evaluating the fatigue life of concrete are
proposed, and the calculated fatigue life agrees well with the experimental result.
出处
《工业建筑》
CSCD
北大核心
1992年第12期8-11,25,共5页
Industrial Construction
