Identification Method of MIMO Linear Dynamical Systems for Modal Analysis of Mechanical Structures

A parameter identification method is proposed that can be used to evaluate dynamic characteristics of mechanical structures modeled as multi-input multi-output linear dynamical systems. The discrete transfer function matrix is identified in two steps, one for the denominator and the other for the numerators, where the model order is determined with the aid of a `prediction´ error function. The continuous counterpart is then obtained by herein developed formula that links discrete and continuous models, from which vibration modal parameters such as natural frequencies and damping factors are derived. Finally, we applied the method for the analysis of a test structure, and verified its practical usefulness.