Experimental Validation of the Constant Level method for Identification of Nonlinear Multi Degree of Freedom Systems

System identification methods for nonlinear dynamical systems could find uses in many applications such
as condition monitoring, finite element model validation and stability determination. The effectiveness of
existing nonlinear system identification techniques is limited by various factors such as the complexity of
the system under investigation and the type of nonlinearities present. In this work, the Constant Level
Identification approach, which can identify multi degree-of-freedom systems featuring any type of
nonlinear function, including discontinuous functions, is validated experimentally. The method is shown
to yield accurate identifications of an experimental dynamical system featuring two types of stiffness
nonlinearity. The full equations of motion are accurately extracted, even in the presence of a
discontinuous nonlinearity.