Identification of Rigid Body Properties of 3-D Frame Structure by MCK Identification Method

This paper presents the result of using a spatial matrix identification method to estimate the rigid body properties of a frame structure. Frequency response functions in three directions at 10 points of the structure are measured by hammer testing. The boundary condition of the structure is free-free. Using the single-input-multiple-output FRFs, the identification method can estimate the rigid body properties of the structure with practical accuracy. The rigid body properties are estimated in three different conditions. The first estimation is done using FRFs up to a frequency between the third and the fourth resonant frequency. The second estimation is carried out using FRFs up to a frequency between the second and the third resonant frequency. The last estimation is carried out using FRFs up to a frequency between the first and the second resonant frequency. All results are practically accurate.