Hide/Show Apps

Seismic energy dissipation in deteriorating systems through low-cycle fatigue

Energy dissipation characteristics of structural members which exhibit both strength and stiffness deterioration under imposed displacement reversals are investigated. In the experimental part, 17 reinforced concrete beam specimens were tested under constant and variable amplitude inelastic displacement cycles. The constant-amplitude tests were employed to determine the low-cycle fatigue behaviour of specimens where the imposed displacement amplitude was the major variable. A two-parameter fatigue model was developed in order to express the variation of dissipated energy with the number of displacement cycles. This model was then used to predict the energy dissipation of test specimens subjected to variable-amplitude displacement cycles simulating severe seismic excitations. It has been demonstrated that the remaining energy dissipation capacity in a forthcoming displacement cycle is dependent on the energy dissipated along the completed displacement path. Moreover, it is observed that total energy dissipation is dependent on the length of the displacement path. Copyright (C) 2003 John Wiley Sons, Ltd.