Behavior of deformed bars anchored at interior joints under seismic excitations

Abstract

A mathematical model of a deformed bar anchored at interior joints of ductile moment resisting reinforced concrete frames subjected to severe earthquakes is presented. It includes the formulation of an accurate model for the local bond stress-slip relationship, use of a simple model for the stress-strain relationship of the reinforcing steel and the numerical solution of the differential equation of bond. The analytically predicted response of anchored beam bars compares well with tbe results of a series of tests for monotonic and cyclic loading. The influence of major parameters of the behavior of anchored bars is shown by an extensive numerical study. The results of this investigation are used to offer practical recommendations for the anchorage of beam bars at interior joints.