Nonlinear parameter estimation for multi-degree-of-freedom nonlinear systems using nonlinear output frequency-response functions

Based on the concept of nonlinear output frequency-response functions (NOFRFs), a novel algorithm is developed in this paper to estimate the nonlinear stiffness and damping parameters for multi-degree-of-freedom (MDOF) nonlinear systems. The validity of this algorithm is demonstrated by numerical studies. This work is an extension and complement of the authors’ previous studies, which involve the study of the properties of the NOFRFs of MDOF nonlinear systems, and the estimation of the system linear stiffness and damping parameters. These results build up a NOFRF-based systematic approach for the analysis of MDOF nonlinear systems.