A study on the effect of material nonlinearity on the generation of frequency harmonics in the response of excited soil deposits

This paper explores the generation of harmonics of a monochromatic excitation frequency in the stress response of an excited soil deposit. The relationship between the level of nonlinearity in the soil and the generation of harmonics is investigated in terms of a simple hysteretic stress-strain model. Centrifuge tests of soil deposits subjected to base excitation are used to confirm numerical inferences. Effects of harmonics generation were also analyzed in nonlinear and equivalent-linear numerical simulations of an excited soil deposit. It is shown that the harmonics are present in both physical experiments and nonlinear numerical simulations, but cannot be captured by equivalent-linear analyses.