Using linear model reduction to investigate the dynamics of structures with local non-linearities

Abstract 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 are demonstrated by obtaining the receptance of a discrete and a continuous system with cubic stiffening discrete springs, using the harmonic balance method. Time simulation, using the reduced model, is also demonstrated by computing the Poincare map of a pinned-pinned beam with backlash. The methods provide satisfactory results providing sufficient degrees of freedom are retained in the reduced model and these retained degrees of freedom are chosen with some care.