An Iterative Algorithm for Modal Analysis based on Structured Matrix Fractions

This paper presents an identification algorithm dedicated to the Modal Analysis of physical objects. This algorithm was specifically designed to process cases where short duration tests with multiple-input excitations are used to identify the system. To conform to these particular conditions, an iterative identification method was developed. It makes use of an appropriate parametrization of multivariable transfer functions based on structured matrix fractions. The identification problem is solved in the frequency domain using an output-error formulation. This paper details this algorithm which is evaluated on an example illustrative of the in-flight modal analysis of an aircraft.