Abstract
The purpose of this paper is to determine a location with additional mass and stiffness in component modal tests. Additional mass is expressed as difference between two masses that are obtained by reducing mass matrices of a tested component and a structure to an arbitrary degree of freedom. Additional stiffness is found in a similar way. These masses depend on a frequency used in mass matrix reduction and have peaks at different frequencies. These peak frequencies vary with the location of additional mass and it is effective to select the location with large displacement for accuracy of measured frequency in component modal tests. A numerical example shows that the proposed method is effective for measuring accurate frequencies of whole structures.
