Because methods of damping selection are different

therefore there will be a great difference in the results of time domain analysis and frequency domain analysis.In this paper

the results of time domain analysis and frequency domain equivalent linear analysis were compared for single layer homogeneous soils with different thicknesses and multi-layered soil under different ground motions

and the results show that the selection of different target frequencies influencing viscous damping coefficient is the main reason leading to different results in time domain analysis.How to evaluate the Rayleigh damping coefficient in time domain analysis from the hysteretic damping ratio in frequency domain analysis was also discussed so that hysteretic damping can be used more reasonably in time domain site response analysis.In order to reduce the differences of the results of time domain analysis and frequency domain analysis

we had better use complete Rayleigh damping formulation and the first and the third natural frequencies.