Nonlinear modal identification through a nonlinear frequency response surface

This paper presents a novel method for nonlinear modal identification using a nonlinear frequency response surface (NFRS). The approach involves sampling an experimental NFRS through constant-excitation voltage stepped sine testing, eliminating the need for a dedicated controller for testing. By extracting quasi-linear constant-response frequency response functions from the NFRS, linear modal techniques can be employed to determine equivalent modal parameters for various response amplitudes. The method’s performance is evaluated against existing techniques using two experimental benchmark structures, demonstrating its effectiveness in identifying nonlinear modal parameters.