基于机液联合仿真的剪叉机构疲劳寿命分析.docx

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基于机液联合仿真的剪叉机构疲劳寿命分析

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黄向明张特尹人奇刘国良

摘??要：为解决工程机械复杂机液结构的疲劳寿命计算问题，以某型号高空作业平台剪叉机构为研究对象，提出了一种基于机液联合仿真的结构疲劳寿命计算方法.首先，建立了剪叉机构的机液联合刚柔耦合多体动力学仿真模型，分析了剪叉机构在举升过程中的受力情况，确定了极限工况为举升阶段79.2s时刻，提取了各关键铰点处的载荷谱;并通过剪叉机构的油缸压力和结构应力测试实验，验证了动力学仿真模型的正确性;然后，基于联合仿真确定的极限工况和铰点载荷谱，对剪叉臂进行了极限工况下和单位载荷作用下的静力学分析，得到了剪叉臂结构应力分布情况;最后，利用铰点载荷谱和剪叉臂结构应力通过仿真获得剪叉臂疲劳损伤云图，确定了剪叉臂疲劳危险部位主要是剪叉臂各个零部件的连接位置处，为后续的疲劳寿命优化提供了基础.

关键词：剪叉机构;机液联合动力学仿真;刚柔耦合;载荷谱;疲劳寿命

Abstract：Inordertosolvethefatiguelifecalculationproblemofengineeringmachinerycomplexmachine-liquidstructure，thispaperproposedacalculationmethodforstructurefatiguelifebasedonmechanicalandhydraulicco-simulationtechnology，takingthescissormechanismofascissoraerialworkplatformastheresearchobject.Amulti-bodydynamicssimulationmodelofmechanical-hydrauliccombinedrigid-flexiblecouplingofscissormechanismwasestablished，andtheforcestatusintheliftingprocessofscissormechanismwasalsoanalyzed.Theultimateworkingstatuswasdeterminedattheliftingstageof79.2s，whiletheloadspectrumateachkeyhingepointwasextracted.Underthesameworkingstatusofsimulation，thetestexperimentsofoilcylinderpressureandstructuralstresswerecarriedout.Theexperimentalresultsverifiedthecorrectnessofthedynamicssimulation.Then，accordingtotheloadspectrumofthehingepointandtheultimateworkingstatusconfirmedbyco-simulation，thestaticanalysisofscissorsarmsundertheultimateworkingstatusandunitloadingactionwascarriedouttoobtainthestaticstressdistributionofscissorsarmsstructure.Eventually，byusingthehingepointloadspectrumandthestaticstressdistribution，thefatiguedamageandfatiguelifeofscissorarmswereobtained.Theresultsconfirmedthatthemosthazardouspartofscissorsarmsfatiguewastheconnectingpositionofeachpartofscissorsarms，whichprovidedabasisforsubsequentfatiguelifeoptimization.

Keywords：scissorsmechanis