Title:
From Global to Local Deformations of Concrete Frame Members Accounting for Steel Properties (Prepublished)
Author(s):
Drit Sokoli, Albert Limantono, Duy V. To, Jack P. Moehle, and Wassim M. Ghannoum
Publication:
Structural Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
grade 100 reinforcement; high-strength reinforcement; plasticity; rotation; special moment frames; strains
DOI:
10.14359/51744380
Date:
11/22/2024
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, and strength degradation, and can better account for variations in member boundary conditions like axial load. The process of estimating local material strains in concrete members remains challenging, mainly due to the 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.