Here, based on the finite element method (FEM), a dynamic model of a double-span rotor system with slowly varying mass was established. By using Newmark-β numerical integration method, vibration characteristics of the double-span rotor system with slowly varying mass under conditions of different rotating speeds, different slowly varying parameters and different slowly varying positions were analyzed with shaft center trajectory diagram, Poincaré section one, time domain waveform one, frequency spectrum one and 3-D waterfall one. The results showed that when there is a slowly-varying mass in the system, a slowly-varying small frequency division Fr appears at ε times of working frequency, and equidistant frequency divisions with frequency interval of ε•Fn appear on both sides of working frequency and on the right side of Fr; the mass variation amplitude coefficient λ mainly affects vibration amplitude of the rotor system, when λ gradually increases, the amplitude of each frequency component of the system increases, and the system becomes more and more unstable; the slowly-varying time coefficient ε mainly affects the periodicity of the rotor system, when ε changes, multiple and period length of the system periodic motion change significantly; when both two disks of a double-span and dual-disk rotor system have slowly-varying mass, the periodic motion and frequency division components of the system are composed of the superposition of the two disks’, and phenomena near high rotating speed region become more obvious; the study results can provide a theoretical reference for studying dynamics and fault recognition of rotor systems with slowly varying mass in the future.
Key words
double-span rotor system /
slowly varying mass /
FEM /
dynamic characteristics
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References
［1］李以农,郑玲,闻邦椿.一类具有参数慢变的非线性振动系统［J］.重庆大学学报(自然科学版),2000(6):16-18.
LI Yinong, ZHENG Ling, WEN Bangchun. Study on the nonlinear vibration system with slow-changing parameters［J］. Journal of Chongqing University (Natural Science Edition), 2000(6):16-18.
［2］CVETICANIN L. Chaos in rotors with slowly varying mass［J］. Journal of Sound & Vibration, 1995, 185(5):897-901.
［3］CVETICANIN L. Normal modes of vibration for continuous rotors with slow time variable mass［J］. Mechanism & Machine Theory, 1997, 32(7):881-891.
［4］CVETICANIN L. Self-excited vibrations of the variable mass rotor/fluid system［J］. Journal of Sound & Vibration,1998,214(4):685-702.
［5］CVETICANIN L, DJUKIC D. Dynamic properties of a body with discontinual mass variation［J］. Nonlinear Dynamic，2008(52)：249-261.
［6］YU Tao, WANG Jiao, LI Yingjie, et al. Nonlinear dynamics characteristics of rotor system with slowly-varying mass based on time-frequency analysis［J］. Journal of Vibration & Shock, 2014, 33(20):105-110.
［7］YU Tao, LI Yingjie, SUN Wei, et al. Time-frequency feature analysis of rotor system with damage of single/dural slowly-varying mass［J］. Machinery Design & Manufacture, 2014(12):128-131.
［8］YU Tao, HAN Qingkai. Time frequency features of rotor systems with slowly varying mass［J］. Journal of Shock and Vibration, 2011(18): 29-44.
［9］李小彭,姚红良,李鹤,等. 质量慢变转子系统的碰摩故障小波分析［J］.中国机械工程,2006(14):1528-1531.
LI Xiaopeng, YAO Hongliang, LI He, et al. Dynamic properties of a body with discontinual mass variation［J］. Chinese Journal of Mechanical Engineering,2006(14):1528-1531.
［10］李小彭,姚红良,任朝晖,等. 时频分析在质量慢变碰摩转子系统中的应用［J］. 机械制造,2005(10):20-22.
LI Xiaopeng, YAO Hongliang, REN Chaohui, et al. Application of time-frequency analysis in the system of rub impact rotor with slowly varying mass［J］. Machinery, 2005(10):20-22.
［11］毛居全,姚红良,闻邦椿.质量慢变碰摩故障转子系统动力学诊断研究［J］.机械制造,2008(2):54-56.
MAO Juquan, YAO Hongliang, WEN Bangchun. Research on dynamic diagnosis of rotor system with rub impact fault with slowly varying mass［J］. Machinery, 2008(2):54-56.
［12］JIANG Mian, WU Jigang, LIU Shuangqi. The influence of slowly varying mass on severity of dynamics nonlinearity of bearing-rotor systems with pedestal looseness［J］. Shock and Vibration,2018,2018:1-11.
［13］WANG Zongyong, WU Jingdong, WEN Bangchun. Research on pedestal looseness and rub-impact faults of rotor system with slowly varying mass［J］. Journal of Vibration Engineering, 2005, 18(2):167-171.
［14］王宗勇,吴敬东,闻邦椿.支承松动的质量慢变转子系统混沌特性研究［J］.中国机械工程,2005(2):73-76.
WANG Zongyong, WU Jingdong, WEN Bangchun. Study on chaos behaviors of rotor systems with slow-varying mass and pedestal looseness［J］. Chinese Journal of Mechanical Engineering, 2005(2):73-76.
［15］LUO Yuegang, ZHANG Songhe, WU Bin, et al. Nonlinear behavior of pedestal looseness fault rotor-bearing system with slowly varying mass［J］. Applied Mechanics and Materials, 2010, 29/30/31/32:2096-2101.
［16］LUO Yuegang, DU Yuhu, REN Zhaohui, et al. Nonlinear Characteristics of Rub-Impact Rotor-Bearing System with Slowly Varying Mass［C］// Measuring Technology and Mechatronics Automation, ICMTMA ’09. International Conference on. American Institute of Physics, 2009.
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