Structural pounding models with Hertz spring and nonlinear damper

The aim of the study is to show a comparison between the nonlinear viscoelastic model and the Hertzdamp model, both of them considered as Hertz contact law force-based models in conjunction with nonlinear damper. The results for two different impact experiments as well as for shaking table experiments on pounding between two steel towers excited by harmonic waves are used in this study. In addition, a suit of thirty ground motion records from thirteen different earthquakes is applied to simulate pounding between two single degree of freedom systems of different period ratios. The results of the study show that the nonlinear viscoelastic model gives smaller simulation errors in the impact force time histories comparing to the Hertzdamp model. It also provides smaller displacement and acceleration amplifications of the pounding-involved structural response under earthquake excitation. On the other hand, the Hertzdamp model has been found to be more accurate than the nonlinear viscoelastic model in simulation of impact velocity for pounding of structures under harmonic excitation.