ABSTRACT
This chapter provides a fuller context for the frequency response function based methods by describing a number of experimental case studies which apply the theory ‘in anger’ as it were. It provides suggestions for nonlinear system identification demonstrators. The system is recommended for their good behaviour and repeatability and provides a framework to explore possibilities for nonlinear identification. Random excitation is optimal for producing frequency response functions for linear systems. However, stepped-sine excitation is superior for the analysis of nonlinear systems. The chapter provides a comparison between the higher-order diagonal frequency response functions measured at the direct location and the frequency response function diagonals regenerated using identified parameters. It shows the correspondence between the beams and single degree-of-freedom bilinear system is also demonstrable in the time domain. When the system is excited at its first natural frequency by a sinusoid at low amplitude, the acceleration response is a perfect sinusoid.
