Closed-form critical earthquake response of elastic-plastic structures with bilinear hysteresis under near-fault ground motions

Abstract

The double impulse input is used as a good substitute of the near-fault ground motion and the closed-form expression is derived of the bilinear elastic-plastic critical response of a structure under this double input. The closed-form expression is also derived for the non-critical case. Because only the free-vibration appears after each impulse of such double impulse input, the energy balance formulation leads to the derivation of the closed-form expression of a complicated bilinear elastic-plastic response. It is shown that the maximum inelastic deformation can occur after the second impulse different from the case for elastic-perfectly plastic models. The validity and accuracy of the proposed theory are investigated through the comparison with the response analysis to the corresponding one-cycle sinusoidal input and recorded ground motions.