Session Start Date

11-3-2010

Abstract

In Brazil, battened double angle system is one of the systems most used in light truss, however, there are not any specific studies on its behavior, resulting in the fact that the standard procedures do not provide subsidies for the design of this section. Moreover, cold-formed steel si mple angles under compression, mostly with slender legs, have an interesting structural behavior compared to other cold-formed steel shapes. Two critical modes are observed in the elastic stability analysis: (i) global flexural mode in the case of longer members and (ii) a coincident local-plate/global flexural-torsional mode, which is critical for shorter members. Studying the behavior of double angle members is interesting, because in this case, besides the critical modes of the single angle, they also show critical modes, due to the presence of the batten plates that sometimes interfere with the behavior of the syst em. In this work, a nonlinear numerical analysis on the behavior of double angle in battened system is presented. The number of batten plates was varied studying their effectiveness in the nominal axial strength. The sensitivity of the members to initial geometric imperfections was also analyzed. Except for the thin angle specimen (t = 1.5 mm) the results obtained from the nonlinear analysis sh owed that the presence of the batten plates significantly increased the nomin al axial strength of the members. However for an increased number of batten plates the nominal axial strength of the members remained almost constant. It was observed that the members were more sensitive to initial geometric imperfections increasing that to the number of batten plates.

Department(s)

Civil, Architectural and Environmental Engineering

Research Center/Lab(s)

Wei-Wen Yu Center for Cold-Formed Steel Structures

Meeting Name

20th International Specialty Conference on Cold-Formed Steel Structures

Publisher

Missouri University of Science and Technology

Publication Date

11-3-2010

Document Version

Final Version

Rights

© 2010 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Nov 3rd, 12:00 AM

Theoretical Analysis of Cold-formed Steel Battened Double Angle Members under Compression

In Brazil, battened double angle system is one of the systems most used in light truss, however, there are not any specific studies on its behavior, resulting in the fact that the standard procedures do not provide subsidies for the design of this section. Moreover, cold-formed steel si mple angles under compression, mostly with slender legs, have an interesting structural behavior compared to other cold-formed steel shapes. Two critical modes are observed in the elastic stability analysis: (i) global flexural mode in the case of longer members and (ii) a coincident local-plate/global flexural-torsional mode, which is critical for shorter members. Studying the behavior of double angle members is interesting, because in this case, besides the critical modes of the single angle, they also show critical modes, due to the presence of the batten plates that sometimes interfere with the behavior of the syst em. In this work, a nonlinear numerical analysis on the behavior of double angle in battened system is presented. The number of batten plates was varied studying their effectiveness in the nominal axial strength. The sensitivity of the members to initial geometric imperfections was also analyzed. Except for the thin angle specimen (t = 1.5 mm) the results obtained from the nonlinear analysis sh owed that the presence of the batten plates significantly increased the nomin al axial strength of the members. However for an increased number of batten plates the nominal axial strength of the members remained almost constant. It was observed that the members were more sensitive to initial geometric imperfections increasing that to the number of batten plates.