In this paper, analytical models of non-linear systems are obtained by identifying the frequency response functions (FRFs) of their associated linear equations (ALEs). This allows the use of several methods of identification in the frequency domain usually applicable to linear systems. Among other advantages, the cumbersome multidimensional Fourier Transformation required in higher-order frequency response functions (HFRFs) analysis is eliminated. Two theoretical systems are used here as examples, an electrostrictive actuator and a Duffing oscillator. The concept of the non-linear gain constant arises as a simple means of identification. © 2003 Elsevier Ltd. All rights reserved.
Vazquez Feijoo, J. A., Worden, K., & Stanway, R. (2004). System identification using associated linear equations. Mechanical Systems and Signal Processing, 431-455. https://doi.org/10.1016/S0888-3270(03)00078-5