液压挖掘机机械臂应力强度结构优化设计仿真

摘要

液压挖掘机主要机械臂的应力强度对液压挖掘机的工作寿命有很大影响,针对挖掘机主要机械臂应力计算困难,液压缸受力求解复杂的问题,综合虚拟样机技术、有限元和静力学理论,采用有限单元法柔性化动臂和斗杆,利用虚拟弹簧阻尼法建立液压缸等效连接,实现了挖掘机危险工况下的静力学分析.求解挖掘机机械臂应力特性及液压缸受力情况,结果表明,综合考虑机械臂柔性形变和液压缸压缩量的静力学分析能得到更符合实际工况的应力分布;机械臂应力集中区域在动臂与动臂液压缸活塞铰接处以及动臂折弯处;虚拟弹簧阻尼法可以快速有效计算出液压缸受力,为机械臂结构优化设计提供了参考.%Stress intensity of hydraulic excavator arm has a great influence on the hydraulic excavator working life.In order to solve the problems of hydraulic excavator mechanical arm stress calculation and a complicated process of calculating the force of a hydraulic cylinder,combining the virtual prototyping technology,finite element analysis techniques and statics theory,a finite element method was used to establish the flexible model of excavator boom and bucket rod.Furthermore,virtual spring-damper method was used to substitute the hydraulic cylinder and static structural simulation in a dangerous condition was carried out.Finally,the stress of mechanical arm and hydraulic cylinder load were analysized.The results show that the static structure of considering the flexible deformation of the manipulator and the compression of the hydraulic cylinder was more accurate in stress calculation.The stress concentration area is in the joint of boom and boom hydraulic cylinder piston.The virtual spring damping method is an effective method to calculate the force of the hydraulic cylinder.