Seismic Energy Absorption in Simple Structures

In this study the energy absorption in, and the inelastic behavior of, simple structures during strong earthquake excitation are investigated. The purposes of the investigation are to evaluate the performance of structures during various types of ground motion, and to attempt to identify more succinctly, than at present, the factors that influence structural deformation and damage. The investigation focuses on the total amount of energy imparted to a structure, the amount of energy dissipated in the structure by inelastic deformations and that dissipated by damping, the displacement ductility the structure experiences, and the number of yield excursions and reversals it goes through during the excitation. The effects of duration of ground motion on earthquake response also are investigated, and based on the amount of energy imparted to structures a possible effective motion criterion is defined. Two methods of scaling ground motion records for equal damage potential are examined. One is based on the assumption that equal displacement ductility will result in equal damage. The other is based on the assumption that equal energy dissipation by inelastic deformations will result in equal damage. The inverse of the scale factors, derived above, may be used as reduction factors in order to modify elastic response spectra for design purposes.National Science Foundation Grants ENV 77-07190 and PFR 80-0258