Asymptotic expansion of slightly coupled modal dynamic transfer functions
نویسنده
چکیده
In case of non-diagonal modal damping, normal modes of vibration do not decouple modal equations. The usual way to handle such a non-diagonal modal damping matrix is to neglect its off-diagonal elements. In this paper, we propose an approximate method based on an asymptotic expansion of the transfer function. It is intermediate between inversion. Indeed, on the one hand, it allows to partially account for modal coupling and, on the other hand, still allows the modal equations to be solved independently from each other. We first provide the mathematical background necessary to canvass the proposed method, then consider a benchmark against which the benefits of the method are measured. & 2009 Elsevier Ltd. All rights reserved.
منابع مشابه
Coupled Flap-Lag-Torsional Vibration Analysis of Pre-twisted Non-uniform Helicopter Blades
An approximate numerical mthod is presented for analysis and determination of modal characteristics in straight, pretwisted non-unifom helicopter blades. The analysis considers the coupled flapwise bending (out of plane), chordwise bending (in plane), and torsion vibration of both rotating and non-rotating blades. The proposed method is based on the integral expansion of Green functions (struct...
متن کاملCoupled Flap-Lag-Torsional Vibration Analysis of Pre-twisted Non-uniform Helicopter Blades
An approximate numerical mthod is presented for analysis and determination of modal characteristics in straight, pretwisted non-unifom helicopter blades. The analysis considers the coupled flapwise bending (out of plane), chordwise bending (in plane), and torsion vibration of both rotating and non-rotating blades. The proposed method is based on the integral expansion of Green functions (struct...
متن کاملFree Natural Frequency Analysis of an FG Composite Rectangular Plate Coupled with Fluid using Rayleigh–Ritz Method
This study investigates natural frequency analysis of an FG composite rectangular plate partially contacting with a bounded fluid. The material properties are assumed to be varying continuously through the thickness direction according to a simple power law distribution in terms of volume fraction of material constituents. Wet dynamic transverse displacements of the plate are approximated by a ...
متن کاملAsymptotics of basic Bessel functions and q-Laguerre polynomials
We establish a large n complete asymptotic expansion for q-Laguerre polynomials and a complete asymptotic expansion for a q-Bessel function of large argument. These expansions are needed in our study of an exactly solvable random transfer matrix model for disordered electronic systems. We also give a new derivation of an asymptotic formula due to Littlewood (1907).
متن کامل