摘要
应用计及轴力效应的有限单元法对起重机箱形伸缩臂在轴向周期载荷作用下的动力稳定性即参数共振问题进行分析研究。运用Lagrange方程建立周期载荷作用下梁杆系统在小变形情况下参数振动方程,确定箱形伸缩臂结构动力不稳定边界的临界频率方程,并讨论阻尼对箱形伸缩臂动力稳定性的影响。分析结果表明:运用计及轴力效应的有限单元法求解动力稳定问题是非常精确和有效的;随着阻尼系数的逐渐增大,其动力不稳定区域逐渐减小,且对第二动力不稳定区域影响更加明显。
According to the finite element method with effect of an axial force, the dynamic stability is presented for crane＇s telescopic booms under a periodic load, which means a parametric resonance problem. Based on the Lagrange equation, the parametric vibration equation of stepped columns with small deformation under a periodic load is established; then the critical frequency equations of the telescopic booms＇ dynamic instability region are derived; finally, the effect of damping to the dynamic stability of telescopic boom is discussed. The results show that efficient and accurate results for structures consisting of stepped columns can be yielded by using the presented method to analyze dynamic stability. As is demonstrated in the numerical examples, the dynamic instability regions are reducing when the damping coefficient increasing, and it affects more obviously to the second dynamic instability region.
出处
《工程力学》
EI
CSCD
北大核心
2013年第3期377-382,共6页
Engineering Mechanics
基金
国家科技支撑计划项目(2008BAJ09B01-03)
关键词
机械工程
动力稳定性
有限单元法
箱形伸缩臂
周期载荷
mechanical engineering
dynamic stability
finite element method
telescopic booms
periodic load
