Frequency Domain Analysis of Multi-Degree of Freedom in Series Model SSI Effect with Translation and Rotation Input

Based on the multi-degree of freedom in series model, structural displacement amplitude formula is derived in the frequency domain under the translation-rotation input situation, this formula indicates that the soil - structure interaction (SSI) could be considered as adding a correction term M˜ to the mass matrix of the structure with the hypothesis of Rigid foundation. This corrected mass matrix is actually a complex matrix, which related to the input frequency and damping. Equivalent translation-rotation input is coupled with two translation input components U* and Θ*. Besides, we uses case analysis to explain the characteristics of soil - structure interaction (SSI) in frequency domain by the end of this paper.