The effects of linear and nonlinear characteristic parameters on the output frequency responses of nonlinear systems: The associated output frequency response function

A damage identification approach is presented using substructure virtual distortion method which takes the advantage of the fast structural reanalysis technique of virtual distortion method. The formulas of substructure virtual distortion method are deduced in frequency domain, and then the frequency response function of the damaged structure is constructed quickly via the superposition of the frequency response function of the intact structure and the frequency responses caused by the damage-coupling virtual distortions of the substructures. The structural damage extents are identified using the measured modal parameters. Two steps are adopted to increase the efficiency of optimization: the modals of finite element model are estimated quickly from the fast constructed frequency response function during the optimization and the primary distortions of the substructures are extracted by contribution analysis to further reduce the computational work. A six-story frame numerical model and an experiment of a cantilever beam are carried out, respectively, to verify the efficiency and accuracy of the proposed method.

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Optimal Design of 6-DOF Parallel Robot Based on Output Frequency Response Function

2009 International Conference on Measuring Technology and Mechatronics Automation ◽

10.1109/icmtma.2009.624 ◽

2009 ◽

Author(s):

Yifeng Zhang ◽

Yu Yao

Keyword(s):

Optimal Design ◽

Frequency Response ◽

Response Function ◽

Frequency Response Function ◽

Parallel Robot ◽

Output Frequency

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Relationship between harmonic balance method and non-linear output frequency response function approach

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/09544062jmes785 ◽

2007 ◽

Vol 221 (12) ◽

pp. 1533-1543 ◽

Cited By ~ 2

Author(s):

Z K Peng ◽

Z Q Lang

Keyword(s):

Frequency Response ◽

Response Function ◽

Harmonic Balance ◽

Frequency Response Function ◽

Harmonic Balance Method ◽

Balance Method ◽

Output Frequency ◽

Non Linear ◽

Harmonic Components ◽

The Relationship

The current paper is concerned with the investigation of the relationship between the harmonic balance method (HBM) and the non-linear output frequency response function (NOFRF) approach in the analysis of non-linear systems. Both are applied to the Duffing's oscillator to demonstrate their relationships. The results reveal that, if the Volterra series representation of a non-linear system is convergent, the harmonic components calculated by the NOFRFs are a solution of the HBM. Moreover, the simulation studies show that, in the convergent cases, the NOFRF method can give more accurate results for the higher-harmonic components than the HBM. The relationship investigated in the current study between the two methods should help researchers and engineers to understand the HBM and the NOFRF methods.

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