NEHRP Clearinghouse

Title
Optimum Seismic Protection for New Building Construction in Eastern Metropolitan Areas. Ductility Requirements of Multidegree Freedom Systems.
File
PB80105232.pdf
Author(s)
Hong, S. T.; Whitman, R. V.
Source
National Science Foundation, Washington, DC. Engineering and Applied Science., June 1973, 39 p.
Identifying Number(s)
INTERNAL STUDY-35
Abstract
This study addresses the issue of providing and mobilizing work capacity of a structure under strong ground motion so that no structure will collapse by excessive deformation of a certain story while the rest of the building suffers little or no damage. Structures used in the study are a hypothetical 6-story reinforced concrete frame and a hypothetical 6-story steel frame. Both structures are assumed to be of shear-type and are modeled by close-coupled mass-spring systems with masses concentrated at floor levels. Methods of analysis using digital computer simulation for estimating the inelastic behavior of a multidegree freedom system are reported. Input to the program contains the characteristics of the spring system and the earthquake time history. Output of the analysis consists of the natural periods, mode shapes, maximum interstory displacements, ductility factors required, maximum shear forces, and time of occurrence. Analyses of results and conclusions drawn from 31 computer runs are presented. Tables show characteristics of computer runs and a summary of results. Ductility and intensity ratio graphs are included.
Keywords
Ground motion; Buildings; Time series analysis; Earthquake engineering; Earthquake resistant structures; Stress analysis; Ductility tests; Steel structures; Computer applications; Degrees of freedom; Graphic methods; Concrete structures; Tall buildings; Dynamic structural analysis