Braced frame systems offer an attractive solution to the multiple design criteria within performance-based seismic engineering. Their elastic properties provide the stiffness and strength needed to achieve operational performance objectives which are... (more)

Braced frame systems offer an attractive solution to the multiple design criteria within performance-based seismic engineering. Their elastic properties provide the stiffness and strength needed to achieve operational performance objectives which are primarily associated with non-structural performance. If detailed properly, their ductility and energy dissipation capacities can meet even severe demands resulting from extreme events. However, previous research results have indicated that current design methods prevent braced frames with buckling and buckling restrained braces from achieving this. International practicing and research engineers recognize this issue. A recent meeting looking towards engineering steel buildings for the next decade agreed that the development of reliable braced frame systems was a top priority in seismic steel research and to achieve this, a coordinated effort was essential, that PBEE should provide the framework tying the activities together, and that the research community should partner strategically with international research organizations and work collaboratively with industry, professional practice and organizations

This research program and the associated team are the solution to meeting this engineering need. The team includes international researchers from the US, Japan, Canada and Taiwan and the research will utilize two NEES facilities, the NEID/E-Defense Miki Shaking table, and the NCREE Laboratory in Taiwan. The primary objective for this small group is to use advanced materials, experimental and analytical research methods, and international cooperative investigation to develop tools and techniques for seismic performance engineering of steel braced frame systems. To achieve this six primary research phases are proposed: (1) infrastructure and literature review and data analysis, (2) integrated-component and sub-assemblage testing, (3) development and validation of high-resolution and practical simulation methods, (4) integrated-system evaluation through international hybrid testing facilities, (5) development of probabilistic-based engineering tools for performance-based earthquake engineering of braced frame systems, and (6) confirmation of the performance through earthquake simulator testing.

The dynamic behavior of three-dimensional steel braced frame building systems is complex and often highly nonlinear. Assessing seismic performance in the context of the true system response and developing practical engineering tools is a central objective of this proposal. An international, systems approach was adopted to develop the work plan to provide fundamental knowledge needed to carry out the work including an integrated and consistent theoretical basis for understanding how the system components interact to contribute to the overall performance of a system. A key component of the research is an international hybrid test of a prototype structure which will include simultaneous testing at the two NEES facilities (UM and UCB) and the NCREE Laboratory in Taiwan and simulation at the University of Washington. This test will truly use the collaborative facilities of NEES while providing an important confirmation of system behavior and engineering methods based developed as part of the earlier research phases.

This work has a direct, tangible and immediate impact on the seismic safety and performance of a widely used form of construction that many believe to be unnecessarily vulnerable to earthquakes, and accelerate the adoption of innovative technologies and construction practices. Steel structures are ideal systems to focus on since these systems constitute the majority of engineered structures in both the US and Japan. There are more than 3500 fabricators in the US alone, with nearly 50,000 individuals involved in fabrication and erection of steel buildings in the US. The volume of steel used annually in the US on buildings is about 5 million tons, enough to make a 10 mm wire that would circle the globe more than 200 times. Thus, a small improvement in performance or economy will have a disproportionate effect compared to other materials. Our work will make steel buildings more economical, design methods more reliable, and increase the competitiveness of US firms in the global economy. It will bring together, as never before done, professional engineers, researchers in the US, Taiwan, and Japan, as well as representatives from industry and regulatory bodies in an integrated and synergistic fashion. The Advisory Group will assist in the cooperation and coordination to assure practical and useful engineering results. We are committed to NSF’s goals of increasing diversity and international collaboration, as demonstrated by this proposal. The opportunities directly supported by this proposal include professional development short-courses oriented towards the training of faculty and practicing engineers, internship and research opportunities for under-represented groups including Native Americans through the Pacific Alliance LSAMP program, and development of materials for pre-K through 12 students for education and exploration of the seismic response of braced systems. (hide)

Equipment	Component	Equipment Class	Facility
6 DOF Test System	47 ton Steel Cruciform Crosshead	Other Utilities	University of Minnesota-Twin Cities
6 DOF Test System	6 DOF Controller	Other Utilities	University of Minnesota-Twin Cities
6 DOF Test System	Hydraulic Command and Control Computer	Other Utilities	University of Minnesota-Twin Cities
6 DOF Test System	Hydraulic Pump, 190 gpm	Hydraulic Power Infrastructure	University of Minnesota-Twin Cities
6 DOF Test System	North Strongwall, 7' x 35' x 35'	Reaction System	University of Minnesota-Twin Cities
6 DOF Test System	Strong Floor, 5.5	Reaction System	University of Minnesota-Twin Cities
6 DOF Test System	Threaded Adapters (x68)	Other Utilities	University of Minnesota-Twin Cities
6 DOF Test System	West Strong Wall, 7' x 35' x 35'	Reaction System	University of Minnesota-Twin Cities
Calibration Equipment	Invar Bars	Other Utilities	University of Minnesota-Twin Cities
Calibration Equipment	Mitutoyo Calipers	Other Utilities	University of Minnesota-Twin Cities
Calibration Equipment	Mitutoyo Gauge Blocks	Other Utilities	University of Minnesota-Twin Cities
Calibration Equipment	Trimos	Other Utilities	University of Minnesota-Twin Cities
Construction Equipment	25 ft Scissorslift	Other Utilities	University of Minnesota-Twin Cities
Construction Equipment	32 ft Scissorslift	Other Utilities	University of Minnesota-Twin Cities
Construction Equipment	Concrete Bucket 1.5 Cu Ft.	Other Utilities	University of Minnesota-Twin Cities
Construction Equipment	EFCO Components	Other Utilities	University of Minnesota-Twin Cities
Construction Equipment	Scaffolding	Other Utilities	University of Minnesota-Twin Cities
Construction Equipment	Supernuts	Other Utilities	University of Minnesota-Twin Cities
DAQ	Data Acquisition Computer	Other Utilities	University of Minnesota-Twin Cities
DAQ	NI Data Acquisition Board	DAQ Infrastructure	University of Minnesota-Twin Cities
DAQ	NI SCXI-1001	DAQ Infrastructure	University of Minnesota-Twin Cities
DAQ	NI SCXI-1102	DAQ Infrastructure	University of Minnesota-Twin Cities
DAQ	NI-SCXI-1520 8 channel universal strain bridge	DAQ Infrastructure	University of Minnesota-Twin Cities
DAQ	Sensor Connect Boxes	DAQ Infrastructure	University of Minnesota-Twin Cities
Krypton Measurement System	Calibration and Certification Documents	DAQ Infrastructure	University of Minnesota-Twin Cities
Krypton Measurement System	Krypton Calibration Bar	DAQ Infrastructure	University of Minnesota-Twin Cities
Krypton Measurement System	Krypton K600 Controller and Software	Other Utilities	University of Minnesota-Twin Cities
Krypton Measurement System	Metris (Krypton) K600 Camera	DAQ Infrastructure	University of Minnesota-Twin Cities
Krypton Measurement System	Metris (Krypton) LED Strober	DAQ Infrastructure	University of Minnesota-Twin Cities
Krypton Measurement System	Metris (Krypton) LEDs	DAQ Infrastructure	University of Minnesota-Twin Cities
Krypton Measurement System	Space Probe	DAQ Infrastructure	University of Minnesota-Twin Cities
Moving and Lifting Equipment	3 Ton Overhead Crane	Other Utilities	University of Minnesota-Twin Cities
Moving and Lifting Equipment	50 Ton Overhead Crane	Other Utilities	University of Minnesota-Twin Cities
Moving and Lifting Equipment	9000 lb capacity forklift	Other Utilities	University of Minnesota-Twin Cities
Networking	Cisco Catalyst	LAN Infrastructure	University of Minnesota-Twin Cities
Server	AXIS Q7900 Rack	Video Server	University of Minnesota-Twin Cities
Server	Backup Image Server	Computer System	University of Minnesota-Twin Cities
Server	Dell Poweredge 2950 Server	Computer System	University of Minnesota-Twin Cities
Server	HP LeftHand P4300 12TB SATA Starter SAN Solution	Computer System	University of Minnesota-Twin Cities
Server	Raritan Paragon II-UMT442 KVM Switch	Computer System	University of Minnesota-Twin Cities
Server	Tape Library	Computer System	University of Minnesota-Twin Cities
Telecommunication	Video Teleconferencing Unit	Other Utilities	University of Minnesota-Twin Cities
Telepresence	Audio Archiving and Streaming Computer	Other Utilities	University of Minnesota-Twin Cities
Telepresence	Central Control and Configuration Computer	Other Utilities	University of Minnesota-Twin Cities
Telepresence	Color Digital Still Image Camera	Camera	University of Minnesota-Twin Cities
Telepresence	Communication Color Video Camera	Camera	University of Minnesota-Twin Cities
Telepresence	Communication Color Video Camera	Camera	University of Minnesota-Twin Cities
Telepresence	Component Video Distributors	Other Utilities	University of Minnesota-Twin Cities
Telepresence	Computer Controlled Pan/Tilt Unit	Camera	University of Minnesota-Twin Cities
Telepresence	DVD Encoders	Other Utilities	University of Minnesota-Twin Cities
Telepresence	Full Matrix Routing Switch	Other Utilities	University of Minnesota-Twin Cities
Telepresence	HD Color Video Cameras	Camera	University of Minnesota-Twin Cities
Telepresence	Microphone	Camera	University of Minnesota-Twin Cities
Telepresence	NEES Client Computer	Other Utilities	University of Minnesota-Twin Cities
Telepresence	NEES Client Laptop Computer	Other Utilities	University of Minnesota-Twin Cities
Telepresence	Robotic Towers	Camera	University of Minnesota-Twin Cities
Telepresence	Stereo Microphone Preamplifier	Camera	University of Minnesota-Twin Cities
Telepresence	Video Encoding Server	Other Utilities	University of Minnesota-Twin Cities
Telepresence	Video Internet Appliance	Other Utilities	University of Minnesota-Twin Cities

Keith Palmer, "Seismic Behavior, Performance and Design of Steel Concentrically Braced Frame Systems" (view)

Adam Christopulos, "Improved Seismic Performance of Buckling Restrained Braced Frames" (download)

Brandon Kotulka, "Analysis for a Design Guide on Gusset Plates used in Special Concentrically Braced Frames" (download)

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