Optimum Arm Geometry for Ductile Modular Connectors
Publication: Journal of Structural Engineering
Volume 132, Issue 5
Abstract
A cast modular connector (MC) has been developed for use as an energy dissipating detail in seismic-resistant bolted steel moment frames. The MC relies on a series of variable section elements (arms) to minimize plastic strain demand and a stiff end region joined by a base to virtually eliminate bolt prying forces and provide a hysteresis characteristic absent of degradation. The MC was developed through a comprehensive program that included heavy industry partner involvement, analytical research, and experimental verification. This paper describes the portion of the analytical research focused on establishing the optimum geometry for the energy-dissipating arm elements. Key parameters were evaluated through parametric studies using nonlinear (material and geometry) finite element analysis and supported by basic theoretical models. The outcome was a set of optimum geometric ratios covering width reduction, length to thickness, aspect ratio, and fillet radius. A MC prototype was cast on the basis of these recommendations. These prototypes were tested under monotonic and cyclic loading and exhibited remarkable ductility, far exceeding qualifying rotational capacities.
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Acknowledgments
This research was supported by NSF CAREER Award Grant No. NSFCMS-01-96120. Supplemental funds were provided by the American Institute of Steel Construction (AISC) and the Steel Founder’s Society of America (SFSA). The computer laboratory was provided through a grant from Intel, Inc.; finite element software was donated by industry partner Swanson, Inc. (ANSYS). The writers are grateful for this support. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the writer(s) and do not necessarily reflect the views of the National Science Foundation.
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Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 132 • Issue 5 • May 2006
Pages: 705 - 716
Copyright
© 2006 ASCE.
History
Received: Sep 8, 2003
Accepted: Oct 17, 2005
Published online: May 1, 2006
Published in print: May 2006
Notes
Note. Associate Editor: Brian Uy
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