professor ben schafer's thin-walled structures research group - johns hopkins university
Direct Strength Method for the Design of Cold-Formed Steel Members with Perforations
Note: The research reported on this page is from a project sponsored by the American Iron and Steel Institute. The project initiated in the summer of 2005. The draft final report was released in July 2008.
Abstract The recently adopted Direct Strength Method has opened the potential for the Specification to encourage the creation of highly optimized and efficient cold-formed steel members by integrating numerically determined elastic buckling loads directly into the design process. A significant current shortcoming of Direct Strength design is that it does not apply to members with perforations (holes). Perforations are commonly used in nearly all cold-formed steel applications and therefore extension of Direct Strength design to members with holes is sorely needed. A three phase (year) proposal is proposed herein to address this shortcoming. The first phase focuses on using existing data coupled with finite element analysis to efficiently provide a means to bring conventional members with holes into the Direct Strength procedures. Phases 2 and 3 focus on more in-depth theoretical challenges and experimental validation so that a rational analysis method can be provided for any cold-formed steel member with perforations, including unique configurations such as flanged holes, slotted holes, and the like. Specific budgets are provided for the three separate phases. A rational analysis method for designing any cold-formed steel member with holes stands to significantly increase the flexibility of cold-formed steel applications and allow industry and practicing engineers to take full advantage of the potentials of the Direct Strength design method.
Progress report 6 (report) - July 2008
Papers, ballots, and design examples are now housed at Virginia Tech Assistant Professor Cris Moen's website. As of August 2010 DSM with holes for columns has been approved by AISI subcommittees and final approval is anticipated in Spring 2011. Work on DSM with holes for beams continues in Professor Moen's research.
last updated 08/13/10
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