基于韧性的混凝土轴压疲劳损伤演化研究  

RESEARCH ON FATIGUE DAMAGE OF CONCRETE UNDER UNIAXIAL COMPRESSION ON THE BASIS OF TOUGHNESS

作　　者：易成[1] 范永魁[1] 朱红光[1] 王建强[1] 

机构地区：[1]中国矿业大学"煤炭资源与安全开采"国家重点实验室,北京100083

出　　处：《工程力学》2010年第8期113-119,共7页Engineering Mechanics

基　　金：国家自然科学基金项目(50478077);煤炭资源与安全开采国家重点实验室开放基金项目(SKLCRSM09KFB08);国家重点基础研究发展计划项目(2010CB732002)

摘　　要：分析了混凝土压缩疲劳寿命的主要影响因素,认为静载下的韧度可以衡量其疲劳寿命;确定了适合的韧度表示方法,建立了混凝土材料静力韧度指标和疲劳韧性之间的关系表达式,从而以静力韧度的测量来代替疲劳韧性,可以大大减少工作量。建立了材料疲劳韧性随疲劳次数耗散模型的数学表达式。在试验基础上,以疲劳韧性消耗作为损伤变量,推导出以静载韧度表达的混凝土疲劳损伤演化方程,发现损伤发展率呈三阶段规律。经对比验证,在不同应力水平下,以静载韧度表示的损伤演化规律与用疲劳韧性表达的损伤规律吻合较好。Based on the analysis of main influencing factors of concrete fatigue life under uniaxial compression, it is proposed that the static toughness of the concrete can be used to evaluate its fatigue life. A proper index is proposed to calculate the static toughness, and meanwhile the relationship between static toughness and fatigue toughness is established according to the theoretic analysis. Then, a new mathematical toughness dissipation model expressed with static toughness is established. On the basis of the model, and the fatigue toughness dissipation as a damage variable, a fatigue damage evolution equation of concrete under compression is derived, and a three-stage damage evolution law is demonstrated from the results. It is verified that the damage evolution law expressed with static toughness correspond well with the damage evolution law expressed with the fatigue toughness measured from the fatigue test.

关 键 词：混凝土 轴压疲劳 疲劳韧性 静力韧度指标 损伤演化 

分 类 号：TU501[建筑科学—建筑技术科学]