叶片轮盘组合体模型的多点激振试验研究

 本文介绍了利用我院研制的电涡流激振器在叶轮组合体模型上实现非接触式多点激振的试验研究情况,分析了试验原理,论证了分离纯模态的激振力布点调力调相准则;列出了各模型的试验结果,并对叶片轮盘耦合振动的若干规律作了探讨。文中,还阐明了在复杂结构振动试验中采用多点激振的意义和需要解决的一些问题。

AN EXPERIMENTAL INVESTIGATION ON MULTI-POINT EXCITATION OF BLADED DISC ASSEMBLY MODELS

An experimental investigation on multi-point non-contact excitation of the bladed disc assembly models has been carried out by using electric-eddy current exciters.The simple criteria of multi-point exciting force distribution for separation into pure modes and of regulating the amplitudes and phases of exciting forces are proposed and proved （see equation 10）. Thus, it is convenient to separate the pure modes and to measure the modal parameters by means of the criteria.Some behaviours of coupled vibration of bladed discs are concluded, that is （ 1 ） The natural frequencies of coupled vibration （NFCV） rise with the increase of the number of nodal diameters of the disc, when the principal deformation of the blades is flexure and decrease a little with the increase of the number of nodal diameters of the disc if the principal deformation of the blades is torsion; （ 2 ） The NFCV decrease with the increase of the number of blades when the principal deformation of blades is flexure; however, the NFCV ascend a bit with the increase of the number blades if the principal deformation of blades is torsion; （ 3 ） When the disc vibrates with nodal diameters more than two mode shapes can be excited at a same NFCV, and the nodal lines of the disc have a phase difference only.