Frequency response functions: validity and usefulness in nonlinear system identification (Q2768480)

The paper deals with characterising nonlinear structures which can be represented by polynomial equations. It considers the role of Higher Order Frequency Response Functions (HFRF). The author studies Volterra series when the input is a harmonic function and he obtains the output which depends on certain Frequency Reponse Functions (FRF). This equation shows that the classical first order transfer function is equal to the classical first order FRF only for linear systems. The result is physically interpreted. The theoretical result can be applied experimentally very simply to measure the approximate HFRF.NEWLINENEWLINE The transfer functions can offer more insight into the type of nonlinearities present in dynamical structural testing.