冻融后疲劳寿命影响系数模型研究  

RESEARCH ON A MODEL OF THE INFLUENCE COEFFICIENT FOR PRE-FREEZE-THAWING FATIGUE LIFE

作　　者：刘荣桂[1] 刘涛[1] 张益多[1] 高嵩[1] 陈妤[1] 

机构地区：[1]江苏大学土木工程系,江苏镇江212013

出　　处：《工业建筑》2010年第6期5-8,20,共5页Industrial Construction

基　　金：国家自然科学基金项目(50878098;50908103);江苏大学第七批科研立项(07A078)

摘　　要：为探索预应力结构在侵蚀环境作用下的工作机理和寿命,对冻融后疲劳侵蚀环境下结构疲劳寿命的主要因素及相对关系进行研究。在试验研究的基础上,采用统计分析的理论,推导出多元曲线关系式;通过大量试验数据,测定和分析经受不同冻融次数T、预应力等级S的试验构件的疲劳寿命,并建立预冻融疲劳寿命影响系数C的模型。结果表明:随着冻融次数T的增加,同一系列预应力构件的预冻融疲劳寿命影响系数C不断下降;而当冻融次数T一定时,预冻融疲劳寿命影响系数C与预应力度S表现出较为复杂的往返性关系,高冻融次数对较高预应力构件的预冻融疲劳寿命影响系数C的影响较大。所得模型可在已知环境和结构等条件下,求出给定可靠概率的疲劳寿命影响系数值和疲劳寿命预测值。To explore working mechanism and life of prestressed structure under pre-freeze-thawing environment which includes freeze-thaw and dynamic fatigue,this paper searched the main factors of fatigue life and the relative relations.On the basis of test and statistical theory,this paper deduced multivariate curve relation,with effective variables.A model about pre-freeze-thawing coefficient C was built using many test data of members that had undergone different freeze-thaw times T and had different pre-stressed grade S,whose fatigue lives were measured and analyzed.The results show that with the increase of freeze-thawing times T,the fatigue life influence coefficient C decreases,but when the times T reach a certain value,the coefficient C has a complicated relation with pre-stressed grade S.More freeze-thaw times has more influence on higher grade pre-stressed members than the lower ones.This paper’s model can get the influence coefficient and fatigue life’s predicted value when the survival probability is given.

关 键 词：预应力结构 冻融 疲劳寿命 影响系数 可靠度 

分 类 号：TU378[建筑科学—结构工程]