USING LINEAR-MODEL REDUCTION TO INVESTIGATE THE DYNAMICS OF STRUCTURES WITH LOCAL NONLINEARITIES

This paper considers the application of model reduction methods, which are popular for linear systems, to systems with local non-linearities , modeled using finite element analysis. In particular these methods a re demonstrated by obtaining the receptance of a discrete and a contin uous system with cubic stiffening discrete springs, using the harmonic balance method. Time simulation, using the reduced model, is also dem onstrated by computing the Poincare map of a pinned-pinned beam with b acklash. The methods provide satisfactory results providing sufficient degrees of freedom are retained in the reduced model and these retain ed degrees of freedom are chosen with some care.