Stability analysis of aeroelastic systems based on aeroelastic FRF and condition number

Abstract

Purpose

The purpose of this paper is to analyze the stability of aeroelastic systems using aeroelastic frequency response function (FRF).

Design/methodology/approach

The proposed technique determines the instability boundary of an aeroelastic system based on condition number (CN) of aeroelastic FRF matrix or directly from FRFs data.

Findings

Stability margins of typical section and hingeless helicopter rotor blade in the subsonic flow regimes (quasi‐steady and unsteady models) are determined using proposed techniques as two case studies.

Originality/value

The paper introduces a technique which is applicable not only when aerodynamic and structure analytical models are available but also when there are experimental models for structure and/or aerodynamics, such as impulse response functions data or FRFs data. In other words, the main advantage of the proposed method, besides its simplicity and low memory requirement, is its ability to utilize experimental data.

Citation

Roknizadeh, A.S., Nobari, A.S., Mohagheghi, M. and Shahverdi, H. (2012), "Stability analysis of aeroelastic systems based on aeroelastic FRF and condition number", Aircraft Engineering and Aerospace Technology, Vol. 84 No. 5, pp. 299-310. https://doi.org/10.1108/00022661211255485