Abstract
The nonlinear dynamics of a cracked rotor system in an aircraft maneuvering with constant velocity or acceleration was investigated. The influence of the aircraft climbing angle on the cracked rotor system response is of particular interest and the results show that the climbing angle can markedly affect the parameter range for bifurcation, for quasiperiodic response and for chaotic response as well as for system stability. Aircraft acceleration is also shown to significantly affect the nonlinear behavior of the cracked rotor system, illustrating the possibility for on-line rotor crack fault diagnosis.
Similar content being viewed by others
Abbreviations
- c m :
-
Mass center of disk
- D :
-
Dimensionless external damping ratio (=2ε/Ω)
- e :
-
Unbalance eccentricity of disk
- K:
-
Stiffness of uncracked rotor
- K ν :
-
Stiffness of cracked rotor in crack direction
- ΔK ν :
-
The largest stiffness change in crack
- ΔK :
-
Stiffness change ratio (=ΔK η/K)
- m :
-
Mass of disk
- O 1 :
-
Center of the line connecting the two bearing centers
- O 3 :
-
Center of disk
- r :
-
Deflection of disk center
- r nmax :
-
Maximum amplitude of per revolution
- r v :
-
Static weight deflection (=mg/K)
- t :
-
Time
- U :
-
Unbalance parameter (=e/r v)
- (x, y, z) :
-
Inertial co-ordinates
- x, y, z :
-
Displacements of the center of the line connecting two bearing centers in coordinates(x, y, z)
- x ′nO ,z ′nO :
-
Dimensionless initial velocity of aircraft before acceleration
- x ′n ,z ′n ,x ′'n ,z ′'n :
-
Dimensionless velocity and acceleration of the aircraft
- (x 1,y 1,z 1), (x n,y n,z n):
-
Deflection and dimensionless deflection of disk center in coordinatesO 1 X 1 Y 1 Z 1(x n=x 1/r v,Yn=y 1/r v,zn=z 1/r v)
- \(\bar x_n \) :
-
Mean value of the displacement inX 1
- α:
-
The obliquity of aircraft, i. e. the angle between the line connecting two bearing centers and the horizontal line
- β:
-
The angle between the crack center line and unbalance direction (crack angle)
- ε:
-
External damping ratio (=c/2mω c)
- ϕ 0 :
-
Initial whirl angle
- ϑ:
-
Rotating angle of co-ordinates (σ, η, ξ)
- θ 0 :
-
Initial unbalance angle
- τ:
-
(=ωt)
- τ 1 :
-
Cycles of rotor
- τ r :
-
(=ω rt)
- ϕ:
-
The angle between crack center line and the line connecting the bearing center and disk center, angle determining degree of opening of crack
- ω:
-
Rotation speed
- ω c :
-
Critical speed of uncracked rotor (\( = \sqrt {{K \mathord{\left/ {\vphantom {K m}} \right. \kern-\nulldelimiterspace} m}} \))
- ω f :
-
Response angular frequency
- ω r :
-
Whirl speed
- (σ,η,ξ):
-
Body fixed rotating co-ordinates
- (σ′,η′,ξ′):
-
Rotating co-ordinates parallel to (σ,η,ξ)
- Ω:
-
Speed ratio (=ω/ωc)
- Ωf :
-
Dimensionless response angular frequency ratio (=ωf/ωc)
- ·:
-
d/dt
- ':
-
d/dτ
References
Wauer J. On the dynamics of cracked rotors: A literature survey[J].Applied Mechanics Reviews, 1990,43(10):13–17.
Wu M C, Huang S C. Vibration and crack detection of a rotor with speed-dependent bearings[J].International Journal of Mechanical Sciences, 1998,40(6):545–555.
Kicinski J, Ostachowicz W M. Nonlinear analysis of cracked rotors with multiple supports[J].ASME, Design Engineering Division, 1995,84(3):1283–1292.
Prabhu B S, Sekhar A S. Severity estimation of cracked shaft vibrations within fluid film bearings [J].Tribology Transactions, 1995,38(3):583–588.
Sekhar A S, Prabhu B S. Condition monitoring of cracked rotors through transient response [J].Mechanism & Machine Theory, 1998,33(8):1167–1175.
Prabhakar S, Sekhar A S. Detection and monitoring of cracks using mechanical impedance of rotorbearing system[J].Journal of the Acoustical Society of America, 2001,110(5):2351–2359.
Ratan S, Baruh H, Rodrigucz J. On-line identification and location of rotor cracks[J].Journal of Sound and Vibraton, 1996,194(1):67–82.
Zheng J B, Mi Z, Meng G. Bifurcation and chaos of a nonlinear cracked rotor[J].International Journal of Bifurcation and Chaos, 1998,8(3):597–607.
Gasch R. Dynamic behavior of a simple rotor with a cross-sectional crack[A]. In: I Mech E Ed.Proceeding of the Conference on Vibration in Rotating Machinery[C]. London: University of Cambridge, 1976, 123–128.
Meng G, Gasch R. The nonlinear influences of whirl speed on the stability and response of a cracked rotor[J].Journal of Machine Vibration, 1992,4(2):216–230.
Author information
Authors and Affiliations
Additional information
Communicated by Li Li, Original Member of Editorial Committee, AMM
Foundation items: the National “863” Project of China (2002AA412410); the National Natural Science Foundation of China (10325209,50335030)
Biographies: Lin Fu-sheng (1965≈)
Rights and permissions
About this article
Cite this article
Fu-sheng, L., Guang, M. & Hahn, E. Nonlinear dynamics of a cracked rotor in a maneuvering aircraft. Appl Math Mech 25, 1139–1150 (2004). https://doi.org/10.1007/BF02439866
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02439866