Damping augmentation of a rotating beam-tendon system via internally placed spring-damper elements

Aeroelastic characteristics of a rotating blade axially loaded by an internally guided tendon

“…Although the rigid attachments are used to guide the tendon in this paper, according to previous studies [15,16], the properly-designed spring-damper or inerter-damper tendon-guiding elements can be used to replace the rigid attachments in order to increase the damping of the blade-dominated modes for further resonance mitigation. Such a configuration may also be applicable when aerodynamics is considered.…”

Vibration control of a rotating Timoshenko beam-tendon system via internal guiding inerter-dampers

“…In this section, the rotating beam-tendon system is modelled using the primary analytical method previously introduced in the similar context in [9]. The analytical tools for conducting the modal analysis and calculating the driving-point receptance at the beam tip are also described here.…”

“…Only the transversal displacements of the beam ( , ) w x t and tendon ( , ) The beam is modelled as a Timoshenko beam, and the tendon as a string. The kinetic energy and potential energy terms of the rotating beam-tendon system due to the vibration in the z direction without the guiding inerter-dampers are the same as those introduced in [9]. They are then discretized by expressing the transversal displacements ( w, t w ) and the cross-sectional rotation of the beam ( ) as the summation of the multiplication of the normalised orthogonal polynomials and the generalised time-dependent coordinates as…”

“…are vectors consisting of the normalised orthogonal polynomials satisfying the geometric boundary conditions of (0) 0 w  , (0) 0   and (0) 0 t w  generated by the Gram-Schmidt process [29] which is further detailed in [9].…”

“…Another problem with the active tendon concept is that the frequencies of some blade modes are not sufficiently sensitive to the axial force, which compromises the idea of changing their frequencies by changing the axial force. A recent study tried to use the spring-damper attachments as the guiding elements [9]. Such a configuration was shown to be capable of increasing the frequencies of the tendon-dominated modes in a similar way to the rigid attachments and increasing the damping of several beam-dominated modes simultaneously.…”