文章编号:1673-5196(2023)01-0044-05考虑应力集中的吊车梁多轴疲劳寿命预测李斌1,李维敦1,郎珊珊*2,李亚楠2(1.甘肃建筑职业技术学院建筑工程系,甘肃兰州730050;2.兰州理工大学机电工程学院,甘肃兰州730050)摘要:钢结构吊车梁在工业建筑中被广泛应用,应力集中的存在导致几何不连续位置在复杂应力下服役.借助有限元法分析吊车梁应力-应变状态,确定危险点位置,并提取应力、应变分量;以应变能密度作为损伤参量并以最大平面为临界面,基于能量准则建立临界面位置数值计算方法,结合有限元结果给出吊车梁临界面位置;考虑吊车梁在非对称载荷下服役,借助Goodman方程进行平均应力修正,并结合Q355D钢近似S-N曲线计算疲劳寿命.该方法考虑了应力集中处多轴应力对疲劳损伤的影响,可以为复杂应力下几何不连续钢构件的疲劳寿命评估提供新方法.关键词:吊车梁;多轴应力;疲劳寿命预测;近似S-N曲线;有限元法中图分类号:TU391文献标志码:AMultiaxialfatiguelifepredictionofcranebeamsconsideringstressconcentrationLIBin1,LIWei-dun1,LANGShan-shan2,LIYa-nan2(1.DepartmentofArchitecturalEngineering,GansuVocationalandTechnicalCollegeofArchitecture,Lanzhou730050,China;2.SchoolofMechanicalandElectricalEngineering,LanzhouUniv.ofTech.,Lanzhou730050,China)Abstract:Steelstructurecranebeamshavebeenwidelyusedinindustrialbuildings.Duetotheexistenceofstressconcentration,partsofcranebeamswithgeometricdiscontinuityareinserviceundermultiaxialstress.Inthispaper,finiteelementmethodisusedtoanalyzethestressandstrainstateofcranebeam,de-terminethepositionofdangerouspoint,andextractitsstressandstraincomponent.Takingtheplanewiththehighestenergydensityasthecriticalplane,amethodtodeterminethecriticalplanebasedonenergycriterionisproposed.Giventhatthecranebeamworksunderasymmetricload,withthehelpofGoodmanequationofmeanstresscorrection,thefatiguelifeofcranebeamiscalculatedbycombiningtheapproxi-mateS-NcurveofQ355Dsteel.Theproposedmethodconsiderstheeffectofthemultiaxialstressneartheregionofstressconcentrationonthefatiguedamageandprovidesanewmethodforfatiguelifeevaluationofsteelmemberswithgeometricdiscontinuousundercomplicatedstress.Keywords:cranebeam;multiaxialstress;fatiguelifeprediction;app...
