Session Start Date

11-5-2014

Session End Date

11-5-2014

Abstract

The structural strength of cold-formed steel lipped channels under combined axial force and biaxial bending moments has been predicted by geometric and material nonlinear collapse analyses performed in ABAQUS and compared to both current, and a newly proposed, beam-column design method. The ABAQUS analyses utilizes a validated modeling protocol calibrated against previous testing by the authors, and including residual stresses and strains, and geometric imperfections; as well as, appropriate cross-section dimensions, member length, and boundary conditions. A total of 75 different lipped channel cross-sections have been selected and the capacity of the beam-column member has been examined under 127 combinations of actions in the P-M1-M2 space (axial load, P, and major-axis, M1, and minor-axis, M2, bending moments). The results have been used to evaluate the current beam-column design method and validate a new Direct Strength Method (DSM) approach for cold-formed steel beam-columns. The newly proposed method provides means to incorporate more realistic stability analyses of cross-sections under the applied actions, where the current design methods include only a linear prediction of the combined actions using “column strength” and “beam strength” as anchor points. Correspondingly, the reliability of both current and newly proposed methods has been evaluated. The newly proposed extensions to the Direct Strength Method show a potential to realize a sizeable strength increase in many situations, and follow the overall trends in the data (P-M1-M2 surface) well; however, additional advancement is needed to realize the complete benefits predicted in the finite element models.

Department(s)

Civil, Architectural and Environmental Engineering

Research Center/Lab(s)

Wei-Wen Yu Center for Cold-Formed Steel Structures

Sponsor(s)

American Iron and Steel Institute (AISI)
Metal Building Manufacturers Association (MBMA)

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.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Nov 5th, 12:00 AM Nov 5th, 12:00 AM

Development of a New Beam-Column Design Method for Cold-Formed Steel Lipped Channel Members

The structural strength of cold-formed steel lipped channels under combined axial force and biaxial bending moments has been predicted by geometric and material nonlinear collapse analyses performed in ABAQUS and compared to both current, and a newly proposed, beam-column design method. The ABAQUS analyses utilizes a validated modeling protocol calibrated against previous testing by the authors, and including residual stresses and strains, and geometric imperfections; as well as, appropriate cross-section dimensions, member length, and boundary conditions. A total of 75 different lipped channel cross-sections have been selected and the capacity of the beam-column member has been examined under 127 combinations of actions in the P-M1-M2 space (axial load, P, and major-axis, M1, and minor-axis, M2, bending moments). The results have been used to evaluate the current beam-column design method and validate a new Direct Strength Method (DSM) approach for cold-formed steel beam-columns. The newly proposed method provides means to incorporate more realistic stability analyses of cross-sections under the applied actions, where the current design methods include only a linear prediction of the combined actions using “column strength” and “beam strength” as anchor points. Correspondingly, the reliability of both current and newly proposed methods has been evaluated. The newly proposed extensions to the Direct Strength Method show a potential to realize a sizeable strength increase in many situations, and follow the overall trends in the data (P-M1-M2 surface) well; however, additional advancement is needed to realize the complete benefits predicted in the finite element models.