A new subspace-based approach to identify nonlinear mechanical structures in the frequency domain

This paper introduces a new frequency-domain subspace-based method for the identification
of nonlinear mechanical systems. The technique exploits frequency data and interprets nonlinearities
as feedback forces exciting the underlying linear system. It is demonstrated using two
academic examples, a Duffing oscillator and a five degree-of-freedom system comprising two
nonlinearities.