弹性环式挤压油膜阻尼器动力学特性系数测试

Experiments on force coefficients identification of elastic ring squeeze film damper

搭建了弹性环式挤压油膜阻尼器(ERSFD)的动力学特性测试试验台。利用两个正交方向的简谐激励对ERSFD进行了激振试验,在轴心为圆时测得了阻尼器的位移和载荷数据,并结合阻尼器质心的运动方程分别识别ERSFD油膜和弹性环的动力学特性系数。结果表明弹性环与油膜均具有显著的阻尼和刚度,其中油膜的阻尼和刚度系数随着凸台高度的升高迅速降低,弹性环的刚度和阻尼受凸台高度影响较小;弹性环的厚度对油膜的刚度和阻尼无显著影响;油膜阻尼随供油压力的升高先增大后不变,油膜刚度随着供油压力的升高先增大后减小。不确定度分析结果表明油膜的四个动力学特性系数Cxx、Cyy、Kxx、Kyy的不确定度分别为12.2%、11.5%、18.2%、12.7%。弹性环的四个动力学特性系数Cxx、Cyy、Kxx、Kyy的不确定度分别为30.7%、33.1%、17.0%、12.8%。

The test rig for the force coefficients of elastic ring squeeze film damper(ERSFD)was set up.ERSFD was excited by two shakers located orthogonally providing harmonic force.The results were obtained under centered circular orbit and utilized for force coefficients identification according to the orbit kinetic of the damper.The results revealed that the damping and stiffness of the film and elastic ring were both significant,the stiffness and damping of the film dropped dramatically with the increase of the height of the pedestal while the force coefficients remained almost constant.The thickness of the ring had little influence on the force coefficients of the film.The damping of the film first turned lager with the increase of feeding pressure and remained constant under high pressure while the stiffness of the film first increased and then decreased a little bit with the increase of feeding pressure.Uncertainty analysis indicates that the uncertainty of the film force coefficients Cxx,Cyy,Kxx,Kyyis 12.2%,11.5%,18.2%,12.7%,respectively while the uncertainty of the force coefficients of the elastic ring Cxx,Cyy,Kxx,Kyyis 30.7%,33.1%,17.0%,12.8%.