预应力混凝土结构在冻融损伤条件下的疲劳寿命预测模型研究  

Durability life prediction of prestressed concrete structures in an erosive environment with fatigue subjoining freezing-thawing circle

作　　者：刘荣桂[1] 付凯[1] 颜庭成[1] 陈妤[1] 

机构地区：[1]江苏大学理学院,江苏镇江212013

出　　处：《建筑结构学报》2009年第3期79-86,共8页Journal of Building Structures

基　　金：国家自然科学基金资助项目(50878098)

摘　　要：为探索预应力结构在侵蚀环境作用下的工作机理与寿命,研究冻融与疲劳侵蚀环境下结构疲劳寿命的主要因素及相对关系,对15根预应力混凝土梁进行了在不同冻融循环次数后的低周疲劳试验。试验结果显示,预应力张拉水平和冻融循环次数是影响预应力混凝土结构疲劳寿命的主要因素。采用损伤力学方法建立了疲劳寿命与冻融循环过程中相对动弹性模量衰减之间的关系,并建立了寿命预测模型。模型计算结果与实测结果表明,预测寿命和实测寿命相比较为符合。本文的工作是对研究预应力混凝土结构损伤机理和改进预应力混凝土结构耐久性设计等方面的有益探索。To explore working theory and life of prestressed concrete （PC） structure under pre freeze-thawing environment which includes freeze-thaw and dynamic fatigue, this paper researched the main complications and the relative relationship, which affected the fatigue life. Based on experimental results for PC structures with 15 specimens, it is shown that the prestressing level and times of freezing-thawing circles are main influence factors to the durability of PC structures in this study. Two analytical models, which were twice damage model and the relatively dynamic elastic modulus law, for the PC structure in erosive environment with fatigue subjoining freezing-thawing circle were conducted by analysis of degradation process of the relatively dynamic elastic modulus. Also, a life expectancy model of the PC structure in the same erosive environment was discussed using theory of damage mechanics. The numerical results were compared with experimental results and a good agreement between the two approaches was observed. The results of this study are useful for the exploration of the mechanism of the PC structure＇s damage and the improvement of design theory concerning the durability of PC structures.

关 键 词：预应力混凝土 冻融循环 疲劳 寿命预测 损伤 耐久性 

分 类 号：TU378.2[建筑科学—结构工程] TU317.1