Identification of non-linear element location in general structural dynamic systems

1 Many engineering dynamic structural non-linearities are ”localized” and their modeling can be greatly simplified if their positions are known. Ideally, the location problem should be a pre-processing stage in a global identification procedure where a full multiple degree-of-freedom identification may be expected to benefit from some simplifying assumptions. The method proposed in this paper is based on a partial system pre-identification. In this process the underlying linear model is extracted using a robust technique developed by the authors suitable for the analysis of general non-linear systems. The position of the non-linear elements is then inferred by calculating the non-linear forces acting on this linear model using the pseudo-inverse approach. The technique is demonstrated using experiments conducted on a beam structure incorporating a local non-linear element.