Vibroacoustic analysis of an unbaffled rotating disk

Abstract

The dynamic and acoustic response of an unbaffled rotating disk, subjected to a space-fixed harmonic lateral force, is investigated. The plate is supposed to be clamped at the inside and free at the outer boundary. The exciting force being space-fixed, the mass and stiffness matrices, obtained from the variational method combined with the Rayleigh-Ritz approach in the rotating frame, are converted back to the nonrotating frame, where the generalized force and the displacements of the plate are evaluated. The related acoustic pressure, neglecting fluid loading, is determined using a boundary element formulation. Special attention has been given to ensure correct modeling of the unbaffled condition on the radiation of the plate. Results are presented to show the effect of rotation for both dynamic response and acoustic radiation. A practical case is also investigated: the circular saw. To simulate the exciting force of the saw, a measurement of the force induced by one tooth has been done. Then, a retarded-time sum has been performed to account for the exact number of teeth.

Squeal noise in simple numerical brake models

“…For a circular plate with a small inner radius and a negligible effect of inplane modes (e.g. as found for blades of circular saws [37]), the thin plate theory is adequate. However, for a brake rotor, i.e.…”

Vibroacoustic Response of an Annular Sandwich Electrorheological Disc

“…where ρ i (i = 1, 2, 3) denotes the material mass density of the i-th layer. Moreover, the variation of the total work done by the external force q(r, ϕ, t) is written as (9) Next, direct substitution of the strain-displacement relations (2) and (3) in (6) yields where the moment resultants in the above equation are defined as [34]…”

“…The sandwich annular ERF plate (a ≤ r ≤ b), which is set in an infinite rigid baffle, consists of a base plate (thickness h 3 ), a constraining layer (thickness h 1 ), and a tunable electrorheological (ER) fluid core layer (thickness h 2 ). For the sake of application, the inner edge of the plate at r = a is supposed to be clamped and the outer edge at r = b is free [8][9][10]15]. The plate is subjected to an applied harmonic transverse distributed load of general form q(r, ϕ, t) = q 0 (r, ϕ)e iωt , where q 0 is the excitation amplitude and ω is the radial frequency.…”

“…Farstad et al [8] reviewed the application of component modal basis method for estimating structure-borne and radiated sound in machine assemblies, and used this method to formulate structurally transmitted vibration and acoustic radiation from a vibrating annular disk. Cote´ et al [9] used the Rayleigh-Ritz and boundary element methods to investigate the dynamic and acoustic response of an unbaffled (clamped-free) rotating disk subjected to a space-fixed harmonic lateral force. Lee and Singh [10] introduced an analytical modal expansion technique for examining the acoustic radiation coupling between interacting structural modes of a thick annular disk with free boundaries.…”

Comparison for the Effect of Different Attachment of Point Masses on Vibroacoustic Behavior of Parabolic Tapered Annular Circular Plate

“…Lee and Singh [16] used the flexural and radial modes of a thick annular plate to determine the self and mutual radiation. Cote et al [17] studied the vibro acoustic behavior of an unbaffled rotating disk. Jeyraj [18] used an isotropic plate with arbitrarily varying thickness to determine its vibro-acoustic behavior using the finite element method (FEM).…”