Automated modal analysis based on frequency response function estimates
Paper in proceedings, 2012

Given measured data as estimated frequency responses of a quasi-linear system, there is a variety of system identification methods that identify a state-space model that gives good correlation to the data. Such methods are the N4SID and the PolyMAX methods. Using these methods, a key problem is to select the proper model order. In this work we investigate a method for the automatic detection of proper model order. The method is based on the statistical evaluation of an ensemble of state-space models all identified from the same basic set of frequency response functions, but with different realizations based on a bootstrapping scheme. We apply the method to real test data.

Good correlations

Test data

Frequency response functions

State-space models

Bootstrapping scheme

Frequency response

Linear systems

Quasilinear system

System identification methods

Statistical evaluation

PolyMAX method

Structural dynamics

Modal analysis

Proper models

Automatic Detection


Vahid Yaghoubi Nasrabadi


Thomas Abrahamsson


Conference Proceedings of the Society for Experimental Mechanics Series. 30th IMAC, A Conference on Structural Dynamics, Jacksonville, 30 January-2 February 2012

2191-5652 (eISSN)

Vol. 5 9-18

Subject Categories

Mechanical Engineering





More information