Title: Plastic Hinge Length of Reinforced Concrete Columns

Author(s): Sungjin Bae and Oguzhan Bayrak

Publication: Structural Journal

Volume: 105

Issue: 3

Appears on pages(s): 290-300

Keywords: axial load; deformation capacity; plastic hinge length

DOI: 10.14359/19788

Date: 5/1/2008

Abstract:
As a column experiences earthquake-induced lateral displacements while supporting gravity loads, severe damage is observed in regions subjected to large moments. These regions are commonly referred to as plastic hinges and they experience large inelastic curvatures. The inelastic curvatures in plastic hinges are typically assumed to be constant over the plastic hinge length, lp, to simplify the estimation of the tip displacement of a column. Therefore, if the plastic hinge length is known, the tip displacement of a column can easily be obtained by integrating curvatures, and vice versa. As part of the research reported in this paper, the effects of axial load and shear span-depth ratio (L/ h) on lp are evaluated experimentally. Based on the experimental observations, a new analytical approach that can be used to estimate lp is presented. Finally, the research findings are synthesized into a simple expression that can be used to estimate lp.