subharmonic vibration meaning in English

次谐波振动
分频振动(频率是基频的分数)
分谐波振动

A new phenomenon is found numerically and experimentally : even if the rotating speed of the rotor is lower , the subharmonic vibration of the rotor - bearing system may be occurred under great disturbance ( unbalance )
通过理论计算和分析发现：提出了即使在较低转速的情况下，只要外激励(不平衡量)足够大，也有可能导致转子出现油膜涡动或者失稳的现象。
In this thesis , a multi - disk rotor supported by two plain journal bearings is used for the numerical and experimental studies . the one aim is to analyze the nonlinear dynamic characteristics of the rotor system under different varying parameters ; the methods of online elimination of the oil whip and subharmonic vibration are developed and studied also . besides the expression of the nonlinear oil film force is proposed , so that the unbalance of the nonlinear rotor system may be identified online
作者在总结了前人大量的有关非线性振动研究工作的基础上，确立了本文的研究目标：一是以工程应用为背景，研究转子-轴承系统由非线性油膜力引起的非线性振动特性以及各种影响因素，力图通过对转子-轴承系统非线性振动特性的分析，找到切实可行的在线消除油膜振荡的办法；二是研究非线性油膜力的表达方法式，使非线性转子系统的不平衡量在线识别成为可能。