professor ben schafer's thin-walled structures research group - johns hopkins university

Sheathing Braced Design of Wall Studs

Note: The research reported on this page is from a project sponsored by the American Iron and Steel Institute - Committee on Framing Standards. The project initiated in the Fall of 2006.

Proposal Abstract

The objective of this research is to develop a reliable design methodology for light-frame wall systems that properly accounts for the behavior of wall studs sheathed by similar, dissimilar, and one-sided sheathing. The developed design methodology will be straight forward in its application, and prescriptive if necessary, such that the method may be readily adopted by the American Iron and Steel Institute – Committee on Framing Standards as a key component to a new edition of the Wall Stud Standard. A combined plan of full-scale experimentation and computational modeling is proposed to develop the new methodology. The full-scale experiments will take advantage of a new testing rig that is being developed in the Johns Hopkins University Structural Testing Laboratory through National Science Foundation funding. This rig will allow for cold-formed steel walls (and members) to be loaded in compression, as well as in-plane bending and/or shear, and out-of-plane bending. The focus of the testing proposed here will be compression and a limited examination of out-of-plane bending (as would develop due to lateral load on the wall). The computational modeling will augment the testing such that (a) further wall system parameters may be studied and (b) the basic behavior of sheathing wall systems may be better understood. Two basic mechanical models have been proposed and used by the AISI standards at different times: the first assumes the sheathing provides a shear diaphragm, the second includes only the local “spring” restraint provided at fastener locations. Both testing and computational modeling are required to further develop and validate the most appropriate mechanical model for predicting the behavior of wall studs with similar, dissimilar, and one-sided sheathing. A three-year project is proposed for addressing these issues.

Project Materials

2002 Specialty Conference Paper on Sheathed Wall Studs (pdf)

AISI-COFS Request for Proposals (pdf)

Proposal (pdf)

Proposal addendum (pdf)

Structural drawings of MDOF testing frame (pdf)

3D model of structural testing frame (pdf)

Notes on related AISI design methods (pdf)

last updated 04/11/08