轴向受压运动梁横向振动特性的数值分析

Numerical analysis of free vibration of an axially moving beam under compressive load

针对Galerkin截断法在计算轴向受载运动梁的固有特性时,低阶频率误差较大的问题,通过引入轴向力作用对试函数进行改进,分析了两端固支和固支-自由边界条件下的Timoshenko运动梁在轴向压力作用下振动特性。结果表明:分析轴向受压运动梁的低阶弹性振动时,轴向力作用不可忽略;改进方法在轴向载荷较大时计算低阶频率有较大改进,而且对于不同边界条件有很好的适应性;轴向压力和运动效应的共同作用更易引起梁的失稳状态。

Errors become larger when using Galerkin method to calculate lower order natural frequencies of an axially moving beam with axial load.By introducing the effect of axial compressive load,the test functions were modified and the vibration characteristics of an axially moving Timoshenko beam under clamped-clamped and clamped- free boundary conditions were investigated.Simulation results showed that the effect of axial load can not be ignored when calculating lower order natural frequencies of the axial moving beam with axial compressive load;the proposed modification approach based on Galerkin method improves the numerical results greatly when the axial compressive load is larger,and it also has a good applicability for different boundary conditions;the common action of axial compressive load and axially moving causes the beam state to be instable more easily.