Developing a method for determining the natural frequency of a structure using multiple combined measurements in the frequency domain

Modal identification of structures using vibration measurement data has attracted considerable attention. Current identification methods can be divided into several groups: single-degree-of-freedom and multi-degrees-of-freedom methods; time domain identification, frequency domain identification. In which, the simultaneous determination of many natural frequencies of the structure from a single measurement data remains a complicated problem, in particular in the presence of noise. The article develops the rational fraction polynomial method using combined measurements in the frequency domain to identify the natural frequencies of structures. The effectiveness of the proposed method is validated by numerical simulations and experimental tests of steel beam.