汽车起重机起升过程吊臂载荷性能预测仿真

摘要

为减少汽车起重机因操作失误及设计不足而引发的安全事故,提高起重机的安全可靠性.研究吊臂载荷对起重机结构的影响,提出了在动态载荷激励下钢丝绳及吊臂的载荷响应模型,重点解决了动态载荷理论公式推导、钢丝绳柔性化处理和吊臂模态和谐响应分析问题.首先引入了钢丝绳阻尼系数,将钢丝绳柔性化处理,建立运动微分方程,推导了相应理论公式.然后在Workbench中建立了起重机伸缩臂的有限元模型,对伸缩臂进行了模态和谐响应分析.最后通过仿真,得到了伸缩臂在不同工况下的位移频率响应曲线、最容易产生共振的频率和共振时伸缩臂的应力变化图.仿真结果表明,伸缩臂动载荷的振幅不断衰减,但发生共振时伸缩臂的最大应力可能超过屈服极限,预测结果准确,为起重机设计和使用操作提供了依据.%To reduce the accidents caused by operational errors and design deficiency of the crane,improve the safety and reliability of the crane,the load response model of the crane structure is proposed under the excitation of dynamic load of wire rope and hanging arm,focused on solving the dynamic load theory formula,wire rope flexible and boom modal and harmonic response analysis.First,damping coefficient and flexible processing of the steel wire rope were introduced,and differential equation of motion was established.Then a finite element model of telescopic boom of the crane was built on Workbench,and the modal and harmonic response analysis of the telescopic boom was carried out.Finally,through the simulation,the displacement frequency response curve of the telescopic boom was obtained,which w most likely to produce the resonance frequency and the stress of the telescopic boom.The results show that the telescopic arm dynamic load amplitude decays,but resonance occurs when the telescopic arm of the maximum stress exceed the yield limit.The prediction results are accurate and provide the basis for the crane design and operation.