Session Start Date

10-17-2002

Abstract

Cold-formed steel bolted moment-connections cannot be considered as rigid because of localised in-plane elongation of the bolt-holes due to bearing of the bolt-shank against the bolt-hole. To therefore calculate the rotational stiffness of such bolted moment-connections, it is necessary to know the load-extension characteristics of bolt-hole elongation. In this paper, a non-linear large- displacement elasto-plastic finite element idealisation of a plain bolt-shank in bearing against a bolt-hole is presented. Graphs of load against bolt-hole elongation are plotted that show good comparison with laboratory test results. A proposed modification of the results allows for the results of a fully-threaded bolt-shank to be predicted. The bolt-hole elongation stiffness so obtained is the main parameter required for the analysis of cold-formed steel frames that use such bolted moment-connections for the joints.

Department(s)

Civil, Architectural and Environmental Engineering

Research Center/Lab(s)

Wei-Wen Yu Center for Cold-Formed Steel Structures

Meeting Name

16th International Specialty Conference on Cold-Formed Steel Structures

Publisher

University of Missouri--Rolla

Publication Date

10-17-2002

Document Version

Final Version

Rights

© 2002 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Oct 17th, 12:00 AM

Evaluation of Bolt-hole Elongation Stiffness for the Stiffness Prediction of Cold-formed Steel Bolted Moment-connections

Cold-formed steel bolted moment-connections cannot be considered as rigid because of localised in-plane elongation of the bolt-holes due to bearing of the bolt-shank against the bolt-hole. To therefore calculate the rotational stiffness of such bolted moment-connections, it is necessary to know the load-extension characteristics of bolt-hole elongation. In this paper, a non-linear large- displacement elasto-plastic finite element idealisation of a plain bolt-shank in bearing against a bolt-hole is presented. Graphs of load against bolt-hole elongation are plotted that show good comparison with laboratory test results. A proposed modification of the results allows for the results of a fully-threaded bolt-shank to be predicted. The bolt-hole elongation stiffness so obtained is the main parameter required for the analysis of cold-formed steel frames that use such bolted moment-connections for the joints.