Title:
From Global to Local Deformations of Concrete Frame Members Accounting for Steel Properties
Author(s):
Drit Sokoli, Albert Limantono, Duy V. To, Jack P. Moehle, and Wassim M. Ghannoum
Publication:
Structural Journal
Volume:
122
Issue:
3
Appears on pages(s):
133-145
Keywords:
Grade 100 reinforcement; high-strength reinforcement; plasticity; rotation; special moment frames; strains
DOI:
10.14359/51744380
Date:
5/1/2025
Abstract:
Performance-based seismic standards establish acceptance
criteria to determine whether structural members can adequately
withstand seismic deformation demands. These criteria primarily
consist of member deformation limits, such as plastic rotation.
There is, however, a shift towards strain-based limits, as strains
can provide more reliable estimates of material damage, strength
degradation, and can better account for variations in member
boundary conditions such as axial load. The process of estimating
local material strains in concrete members remains challenging,
mainly due to paucity of physical models and test data at the strain
level. To address this challenge, a framework based on fiber-section
elements and mechanics-based behavioral models is proposed.
This framework allows for strain demand estimates based on
member-level deformations. Particularly, the framework provides
strain demands on longitudinal bars and concrete within the plastic
hinge regions of frame members while accounting for differences in
steel properties as grade increases.