This award is an outcome of the NSF 06-504 program solicitation "George E. Brown, Jr. Network for Earthquake Engineering Simulation Research (NEESR)" competition. Intellectual Merit: Braced frame systems offer an attractive solution to satisfy multiple design criteria within a performance-based earthquake engineering (PBEE) framework. If detailed properly, their displacement and energy dissipation capacities can meet severe demands resulting from extreme events. However, research results have indicated that current design methods prevent braced frames with traditional and buckling-restrained braces from achieving their potential. 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 are central objectives of this proposal. The consensus of a recent meeting focused on engineering steel buildings for the next decade was that the development of reliable braced frame systems was a top priority in seismic steel research and required the following: a coordinated, international effort, a central PBEE framework to tying the activities together, and collaboration with industry, professional practice and related organizations. This award provides such coordination. The project team includes researchers from the US, Japan, and Taiwan, as well as affiliated researchers from Canada. The research will utilize the NEES facilities at the University of Minnesota (UM) and the University of California, Berkeley (UCB), the NIED/E-Defense Miki shake table in Japan, and the NCREE Laboratory in Taiwan. The primary objective is to use advanced hybrid simulation research methods and international, cooperative investigation to develop performance-based tools and techniques for advanced seismic engineering of steel braced frame systems. Seven primary research phases are proposed: (1) infrastructure and literature and data analysis, (2) integrated-component and subassemblage testing, (3) development and validation of high-resolution and practical simulation methods, (4) integrated-system evaluation through coordinated, international hybrid testing facilities, (5) development of probabilistic-based engineering tools for PBEE of braced frame systems, (6) confirmation of the performance through earthquake simulator testing, and (7) evaluation and validation of the design and analysis tools. A key element of the research is an international hybrid test of a prototype structure that 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. . Broader Impacts: This research 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 constitute the majority of engineered building systems in the United States. This research will make steel buildings more economical, design methods more reliable, and increase the competitiveness of U.S. firms in the global economy. This project brings together professional engineers, researchers in the United States, Taiwan, and Japan, as well as representatives from industry and regulatory bodies in an integrated and synergistic fashion. An Advisory Group will assist in the cooperation and coordination to assure practical and useful engineering results and to provide rapid assimilation of these results by the engineering profession. This research will increase diversity and international collaboration through professional development short-courses oriented towards the training of faculty and practicing engineers, provide internship and research opportunities for Native American undergraduate students through the Pacific Alliance LSAMP program, and develop materials for pre-K through grade 12 students for education and exploration of the seismic response of braced systems.
