剪叉式液压升降机剪叉机构动态强度及疲劳强度研究  

Research on dynamic strength and fatigue strength of scissor mechanism of scissor hydraulic lift

作　　者：王茵[1] 张元常 张大斌[2] WANG Yin;ZHANG Yuanchang;ZHANG Dabin(Guizhou Communications Polytechnic,Guiyang 551403,China;School of Mechanical Engineering,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州交通职业技术学院,贵阳551403 [2]贵州大学机械工程学院,贵阳550025

出　　处：《现代制造工程》2022年第7期127-134,共8页Modern Manufacturing Engineering

基　　金：贵州省科技计划资助项目(黔科合平台人才[2019]5616号)。

摘　　要：针对长期处于循环载荷作用下的液压升降机剪叉机构存在结构开裂的问题,分别对其进行了动态强度与疲劳强度研究,提出了基于有限元+多体刚柔耦合动力学+疲劳分析的联合分析法,对剪叉机构动态强度与疲劳强度进行研究。以某型自行走剪叉式液压升降机为例,利用SolidWorks辅助RecurDyn软件,建立整机多刚体动力学模型,再以HyperMesh/OptiStruct软件对其剪叉机构进行柔性化处理,建立多体刚柔耦合动力学模型,模拟极端工况下作业平台的升降运动行为过程,并提取到剪叉机构关键叉臂的动态应力时间历程;在此基础上,结合名义应力法,利用FEMFAT软件预测得到剪叉机构的疲劳强度。研究结果表明:当前剪叉机构能满足结构强度设计要求;剪叉机构中疲劳强度最薄弱区域位于第3组内叉臂的钣金与矩形管连接处,最小疲劳寿命为6.602×10^(3)次循环,有必要进一步优化结构。研究方法可为类似高空作业平台的动态强度与疲劳强度研究提供有价值的参考。Aiming at the problem of structural cracking in the scissor mechanism of hydraulic lifts under cyclic load for a long time,the dynamic strength and fatigue strength of the scissor mechanism were studied separately,and a method based on FEM(Finite Element Method)+MBRFCD(Multi Body Rigid-Fiexible Coupling Dynamics)+Fatigue analysis was proposed to study the dynamic strength and fatigue strength of the scissor mechanism.The example of a certain type of self-propelled scissor hydraulic lift was taken,SolidWorks and RecurDyn software were used to establish a multi-rigid body dynamic model of the whole machine,and then HyperMesh/OptiStruct software was used to flexibly process the scissor mechanism,a multi body rigid-flexible coupling dynamic model was established to simulate extreme engineering.Under this condition,the lifting motion behavior process of the working platform was extracted,and the dynamic stress time history of the key fork arm of the scissor mechanism was extracted;on this basis,combined with the nominal stress method,the fatigue strength of the scissor mechanism was predicted by FEMFAT software.The research results show that the current scissor mechanism can meet the design requirements of structural strength;the weakest area of fatigue strength in the scissor mechanism is located at the junction of the sheet metal and rectangular tube of the third group of inner fork arm,and the minimum fatigue life is 6.602×10^(3) cycles,further optimizing the structure is necessary.The research method can also provide a valuable reference for the dynamic strength and fatigue strength research of the similar aerial work platforms.

关 键 词：液压升降机 剪叉机构 刚柔耦合动力学 动态强度 疲劳强度 

分 类 号：TH114[机械工程—机械设计及理论]