Critical earthquake response of a SDOF elastic‐perfectly plastic model with viscous damping under double impulse as a substitute for near‐fault ground motion

Abstract

The double‐impulse input is introduced as a substitute for the fling‐step near‐fault ground motion, and a closed‐form solution for the approximate elastic‐plastic response of a structure with viscous damping under the “critical double impulse” is derived. Since only the free vibration appears under such a double impulse, the energy approach plays an important role in the derivation of the closed‐form solution for a complicated elastic‐plastic response with viscous damping. The quadratic function approximation for the damping force‐deformation relationship is introduced. The validity and accuracy of the proposed theory are investigated through comparison of the results of the response analysis to the corresponding one‐cycle sinusoidal input and actual recorded ground motions.