Assessment and Validation of Nonlinear Identification Techniques Using Simulated Numerical and Real Measured Data

摘要

In the last ten years, particular effort has been spent dealing with the identification of multi degrees of freedom nonlinear systems. The ever increasing complexity of the structures has gone along with the increasing sophistication of mathematical techniques, so the structural dynamicist often finds himself with many methods to choose from, each of which is - however - capable of addressing just subsets of the whole problem. In IMAC XXXI, a new (modal) parameters identification toolbox approach was introduced, capable of dealing with the different aspects of the nonlinear phenomenon, namely: detection, characterisation, localisation and quantification. A review of available methods was also presented. This paper brings forward the previous idea, assembling a functional toolbox of techniques useful to estimate the dynamics of nonlinear structures using common test practices, without requiring exotic excitations or setups. These techniques are validated against a 4DOF numerical test case with multiple nonlinearities and, finally, applied to a real aeronautical test structure supplied by industry.