细长桁架臂卸载反弹动应力分布规律及试验  

Distribution law and test of dynamic stress during unloading rebound of slender truss boom

作　　者：刘洋[1] 付玲 刘延斌 尹莉 LIU Yang;FU Ling;LIU Yanbin;YIN Li(College of Engineering and Design,Hunan Normal University,Changsha 410081,China;State Key Laboratory of Construction Machinery,Changsha 410013,China)

机构地区：[1]湖南师范大学工程与设计学院,长沙410081 [2]建设机械关键技术国家重点实验室,长沙410013

出　　处：《振动与冲击》2024年第15期251-260,共10页Journal of Vibration and Shock

基　　金：建设机械关键技术国家重点实验室开放基金项目(SKLCM2022-02)。

摘　　要：为研究细长桁架臂在卸载冲击下的动态响应变化规律,提出了基于等效梁振型函数的桁架臂动应力分布计算模型。根据等效梁振型函数,探讨了卸载后桁架臂动应力分布假设,分析了影响桁架臂卸载反弹动响应的相关参数。以装备细长桁架臂的动臂塔机为对象,建立了桁架臂精细化有限元模型和起重机刚柔耦合模型,通过仿真辨识了应力分布模型的关键参数。实施了动臂塔机系列载荷卸载冲击试验,桁架臂上主弦杆的动应力试验值与理论计算结果误差小于7%,表明动应力分布理论模型与实际相符。通过理论模型预测了极限工况下桁架臂上主弦杆动应力分布状态,发现在最大载荷卸载条件下起重臂动应力峰值超过结构承载极限,为卸载条件下起重机关键结构的优化设计提供依据。Here,to study dynamic response changes of slender truss boom under unloading impact,a calculation model for dynamic stress distribution of a truss boom based on equivalent beam vibration mode function was proposed.Based on the equivalent beam vibration mode functions,the dynamic stress distribution assumption of truss boom after unloading was explored,and relevant parameters affecting unloading rebound dynamic response of truss boom were analyzed.Taking a boom tower crane equipped with slender truss boom as the study object,the refined finite element model of truss boom and a rigid-flexible coupled model of tower crane were established.Through simulation,key parameters of stress distribution model were identified.A series of load unloading impact experiments were conducted for boom tower crane,it was shown that errors between experimental values of dynamic stress on main chord of truss boom and theoretical calculation results are less than 7%,so the theoretical model of dynamic stress distribution agrees well with the actual situation.After predicting dynamic stress distribution on main chord of truss boom under extreme working conditions with the theoretical model of dynamic stress distribution,the results showed that dynamic stress peak values of crane arm exceed the structural load-bearing limit value under maximum load unloading condition to provide a basis for optimization design of key structure of crane under unloading condition.

关 键 词：动应力分布模型 振型函数 桁架臂 刚柔耦合模型 卸载冲击试验 

分 类 号：TH212[机械工程—机械制造及自动化]