Dynamic Ratcheting in SDOF hysteretic damping systems induced by earthquake excitations

• When DR occurs, plastic deformation increases asymmetrically in successive cycles.
• Numerical simulation indicates that DR can occur under earthquake excitations.
• The likelihood of DR occurrence mainly depends on local site conditions.

Dynamic Ratcheting (DR) is a phenomenon in which plastic deformation in a hysteretic damping system increases asymmetrically in successive cycles. In the present paper, DR in single degree-of-freedom (SDOF) systems under earthquake excitation is investigated based on strong motion data collected in California between 2002 and 2012. The characteristics of earthquakes in the time–frequency domain are studied on spectrograms; furthermore, linkages between the spectrogram, displacement time history, and the Fourier Transform are identified to locate intervals during which DR is expected to occur. It is observed that DR occurs for 10 out of 160 studied earthquakes according to the proposed DR investigation procedure. The likelihood of DR seems to mainly depend on local site conditions; however, the likelihood significantly increases as the magnitude of earthquakes increases.