On the separation of a measured structural response in a forced and an ambient part for OMAX testing

The lack of a physically intuitive OMAX approach can be attributed to the difficulty of decomposing the measured joint response in a forced and an ambient part in an accurate way. In this paper, a matrix projection (subspace) approach is developed that achieves this decomposition. It allows to use any experimental and operational modal analysis technique on the forced and ambient parts of the data, respectively, and to combine them for joint modal parameter estimation; here, this is further elaborated for subspace identification. An extensive simulation example illustrates the accuracy and practicability of this approach.