Session Start Date

11-5-2014

Session End Date

11-5-2014

Abstract

An exploratory study is performed herein on the global, local, and distortional buckling behavior of built-up cold-formed steel members constructed using industry standard lipped channel sections. The stability characteristics of these columns under concentric axial compressive loads offers insights on member assembly (e.g. fastener spacing), and on the prediction of buckling loads (e.g., section rigidities) used in design formulations. Currently, built-up column buckling is determined using a modified flexural slenderness ratio, which reduces the buckling capacity in part due to a loss of shear rigidity in the overall member’s interconnections. In this paper, a numerical study is performed to analyze the level of composite action that can be achieved with idealized standard details, and which can then be used subsequently to more accurately predict the composite member strength. A parametric study using elastic buckling analysis was conducted on a representative population of built-up structural columns in ABAQUS. Member cross-sections, fastener spacing, and fastener grouping at the column ends were varied. Notable outputs include elastic buckling loads and column critical slenderness ratios. Buckling loads from the study are compared to code-based equation predictions and show considerable composite action, which can increase a column’s buckling load by up to 85% from its non-composite lower bound, assuming discrete connections. Future work includes experimental testing, nonlinear collapse simulations, and the development of new design formulations.

Department(s)

Civil, Architectural and Environmental Engineering

Research Center/Lab(s)

Wei-Wen Yu Center for Cold-Formed Steel Structures

Sponsor(s)

United States. Department of Defense
United States. Air Force. Office of Scientific Research

Meeting Name

22nd International Specialty Conference on Cold-Formed Steel Structures

Publisher

Missouri University of Science and Technology

Publication Date

11-5-2014

Document Version

Final Version

Rights

© 2014 Missouri University of Science and Technology, All rights reserved.

Comments

Research for this paper was conducted with Government support under FA9550- 11-C-0028 and awarded by the Department of Defense, Air Force Office of Scientific Research, National Defense Science and Engineering Graduate (NDSEG) Fellowship, 32 CFR 168a.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Numerical Studies on the Composite Action and Buckling Behavior of Built-Up Cold-Formed Steel Columns

An exploratory study is performed herein on the global, local, and distortional buckling behavior of built-up cold-formed steel members constructed using industry standard lipped channel sections. The stability characteristics of these columns under concentric axial compressive loads offers insights on member assembly (e.g. fastener spacing), and on the prediction of buckling loads (e.g., section rigidities) used in design formulations. Currently, built-up column buckling is determined using a modified flexural slenderness ratio, which reduces the buckling capacity in part due to a loss of shear rigidity in the overall member’s interconnections. In this paper, a numerical study is performed to analyze the level of composite action that can be achieved with idealized standard details, and which can then be used subsequently to more accurately predict the composite member strength. A parametric study using elastic buckling analysis was conducted on a representative population of built-up structural columns in ABAQUS. Member cross-sections, fastener spacing, and fastener grouping at the column ends were varied. Notable outputs include elastic buckling loads and column critical slenderness ratios. Buckling loads from the study are compared to code-based equation predictions and show considerable composite action, which can increase a column’s buckling load by up to 85% from its non-composite lower bound, assuming discrete connections. Future work includes experimental testing, nonlinear collapse simulations, and the development of new design formulations.