NEHRP Clearinghouse

Title
Relation between Local and Global Damage Indices.
File
PB90173865.pdf
Author(s)
DiPasquale, E.; Cakmak, A. S.
Source
National Center for Earthquake Engineering Research, Buffalo, NY.; National Science Foundation, Washington, DC., August 15, 1989, 82 p.
Abstract
The study is based on the analysis of a database of structures, subjected to simulated earthquake loads on a shaking table, shows that parameter-based global damage indices can be related to local stiffness degradation through operations of averaging over the body volume. The relationship obtained is applied to the case of numerical simulations of damage events as well as to the case of actual structures tested on shaking tables. Some results are also presented, relating parameter-based global damage indices to averages in space and in time of the local plastic strain. The relationship between local and global damage variables is also considered from an empirical point of view. A relationship between the apparent softening (global variable) of the structure and the interstory ductility (local variable) has been established. A set of fragility curves relative to structural limit states have thus been defined.
Keywords
Earthquake resistant structures; Dynamic loads; Damage; Vibration; Structural design; Earthquake engineering; Stiffness; Elastic properties; Ductility; Plastic deformation; Dynamic structural analysis