Hysteretic energy spectrum and damage control

The inelastic response of single-degree-of-freedom (SDOF) systems subjected to earthquake motions is studied and a method to derive hysteretic energy dissipation spectra is proposed. The amount of energy dissipated through in elastic deformation combined with other response parameters allow the estim ation of the required deformation capacity to avoid collapse for a given de sign earthquake. In the first part of the study, a detailed analysis of cor relation between energy and ground motion intensity indices is carried out to identify the indices to be used as scaling parameters and base line of t he energy dissipation spectrum. The response of elastoplastic, bilinear, an d stiffness degrading systems with 5 per cent damping, subjected to a world -wide ensemble of 52 earthquake records is considered. The statistical anal ysis of the response data provides the factors for constructing the energy dissipation spectrum as well as the Newmark-Hall inelastic spectra. The com bination of these spectra allows the estimation of the ultimate deformation capacity required to survive the design earthquake, capacity that can also be presented in spectral form as an example shows. Copyright (C) 2001 John Wiley & Sons, Ltd.