q345 等边角钢腐蚀疲劳性能试验研究

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1、振动与冲击第33卷第2期J0URNAL0FVIBRAT10NANDSHOCKV01．33No．22014Q345等边角钢腐蚀疲劳性能试验研究张春涛，范文亮，李正良(1西南科技大学土木工程与建筑学院，四川绵阳621010；2重庆大学土木工程学院，重庆400045)摘要：针对角钢构件在输电塔线体系服役期间因环境腐蚀与风致振动耦合作用导致疲劳性能退化，而构件腐蚀疲劳试验成本高、耗时久、难度大等限制因素所致试验资料匮乏问题，基于节省成本、提高精度思路，结合单点一似然法与相关系数优化法，提出确定腐蚀疲劳S—N曲线表达式参数的改进回归分析方法，构造与之对应的实

2、现算法，建立随腐蚀时问变化的t—P—S—N曲面表达式；通过三组不同腐蚀时间的18根足尺试件疲劳试验，研究Q345等边角钢腐蚀疲劳破坏模式，分析P—s—N曲面方程中各参数随腐蚀时间的变化规律，并结合理论分析建立Q345等边角钢构件t—P—S～N曲面模型。采用该模型探讨不同腐蚀时间内Q345等边角钢构件疲劳寿命的变化规律。结果表明，相同疲劳荷载水平作用下试件疲劳寿命随腐蚀时间急剧减小；同一腐蚀时间内疲劳寿命受腐蚀因素的影响程度随荷载的减小而增加。关键词：腐蚀疲劳；Q345等边角钢；单点一似然法；相关系数优化法；回归分析中图分类号：TU312+．3；TU

3、317+．2文献标识码：AExperimentalresearchonthecorrosionfatiguepropertiesofQ345equalanglesZHANGChun—tao，FANWen—liang。，LIZheng—liang，(1．SchoolofCivilEngineeringandArchitecture，SouthwestUniversityofScienceandTechnology，Mianyang621010，China；2．SchoolofCivilEngineering，ChongqingUniversity，C

4、hongqing400045，China)Abstract：Becauseofthecouplingbetweenenvironmentcorrosionandwind·inducedvibration，thefatiguepropertiesofangleswilldegenerateduringserviceperiod．Fromtheviewpointofcostsavingandprecisionimproving，animprovedregressionmethodforestimatingS—Ncurvesofcorrosionfati

5、guewasproposedbycombiningthesingle—pointlikelihoodmethod(SPLM)withtheoptimizationofcorelationcoeficient．TheimplementationalgorithmfortheimprovedSPLMwasalsoproposed．Accordingtotheimprovedmethod，anexpressionforthet-P—S—Nsurfaceofcorosionfatiguewaspresented．Meanwhile，thecorosionf

6、atigueofthreetypesof18Q345equalanglesindifferentcorosiontimedurationweretested．ThecorosionfatiguefailuremodesofspecimenswereobservedandthevariationofP—S—Ncurvesindifferentcorosiontimedurationwasinvestigated．Thenthet-P—S—NsurfacemodelofQ345equalangleswasachievedandthevariationl

7、awofQ345equalangles’fatiguelifewasobtained．Itisfoundthatthefatiguelifedecreasessharplywiththeincreaseofcorosiontimeunderthesameload；theeffectofcorosiononfatiguelifebecomesmoreandmoreseriouswiththedecreaseofloadinthesamecorosiontime．Keywords：corosionfatigue；Q345equalangles；sing

8、le—pointlikelihoodmethod；optimizationmethodofcorrelationeoemc