Proceedings ArticleDOI
Influence of nonlinear elastomer on isolated lag dynamics and rotor/fuselage aeromechanical stability
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TLDR
In this paper, the effect of nonlinearities of an elastomeric bearing on isolated lag dynamics and coupled rotor/fuselage ground resonance stability of an idealized bearingless rotor blade is studied.Abstract:
This paper presents a study on the effect of nonlinearities of an elastomeric bearing on isolated lag dynamics and coupled rotor/fuselage ground resonance stability of an idealized bearingless rotor blade. The rotor blade is modeled as an elastic beam with a nonlinear elastomer and a rigid torque tube. First, amplitudedependent natural frequency of the blade in lag mode is analyzed using numerical perturbation technique. Then the problem of amplitudedependent stability of the coupled rotor/fuselage system under ground resonance condition is investigated. The stability of the system is analyzed by two approaches, namely, 1) by eigenanalysis of the linearized equations and 2) by response of the nonlinear system to an initial disturbance by time integration. The results of the eigenanalysis indicate that the effect of amplitude seems to be more dominant on the progressive lag mode damping than on regressive lag mode damping. It is also observed that so far as the stability in ground resonance is concerned there exist optimum locations for the attachment of both the elastomer and torque tube. Results of the time-domain analysis of the nonlinear equations indicate clearly that the stability of the system is dependent on the magnitude of initial disturbance.read more
References
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Journal ArticleDOI
Time Domain Modeling of Linear Viscoelasticity Using Anelastic Displacement Fields
TL;DR: In this paper, a time domain model of linear viscoelasticity is developed based on a decomposition of the total displacement field into two parts: one elastic, the other anelastic.
Journal ArticleDOI
Nonlinear Behavior of an Elastomeric Lag Damper Undergoing Dual-Frequency Motion and its Effect on Rotor Dynamics
Journal ArticleDOI
Nonlinear vibrations of a beam-spring-mass system
Mehmet Pakdemirli,Ali H. Nayfeh +1 more
TL;DR: In this paper, the nonlinear response of a simply supported beam with an attached spring-mass system to a primary resonance is investigated, taking into account the effects of beam midplane stretching and damping.
Journal ArticleDOI
A time-domain non-linear viscoelastic damper model
Farhan Gandhi,Inderjit Chopra +1 more
TL;DR: In this paper, a viscoelastic solid model consisting of a combination of linear and non-linear springs and dashpots is developed to represent an elastomeric damper, and a nonlinear constitutive differential equation is derived to characterize the damper behaviour in the time domain.
Journal ArticleDOI
Finite Element Analysis for Bearingless Rotor Blade Aeroelasticity
N. T. Sivaneri,Inderjit Chopra +1 more
TL;DR: In this article, the spatial dependence of the equations of motion is discretized by dividing the flexbeams, the torque tube, and the outboard into a number of elements.
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