The Department of Structure Mechanics of the University of Granada organizes the Seminar Seismic performance of modern concentrically braced frames. The experts will deal with the seismic behaviour of concentrically braced frames for use in regions of high seismic risk in the United States. The Seminar is one of the activities programmes every year by seminar José Antonio García García, a meeting point to spread research news generated in the University of Granada as well as in other reference centres, both aimed at professors and students.
When earth shakes
In recent years, there has been a shift in typical steel construction from moment frames to concentrically braced frames for use in regions of high seismic risk in the United States. Given the large increase in popularity, it is alarming to find that large-scale testing of subassemblages or components of special concentric braced frames is sparse, particularly with frames containing conventional buckling braces and modern construction details. Rigorous analytical modelling of structures with proportions and details typical to those used in concentrically braced frames today are also limited. These models are paramount to adequately predict and assess performance of these structures when subjected to severe ground shaking.
As such, a series of investigations are underway at UC Berkeley under the supervision of Prof. Stephen Mahin aimed at understanding and improving the seismic performance of concentrically braced steel frame structures. To date, extensive analytical studies have been carried out on systems with conventional and buckling restrained bracing. Tests on a limited number of full-scale pipe and HSS tube braces have been carried out along with large scale testing of a twostory SCBF frame utilizing typical, modern detailing. These tests have been conducted to supplement available data on the behaviour of conventional buckling braces and to develop improved numerical models to simulate the behaviour of conventional braced frames, including their failure due to low cycle fatigue. The primary objectives of the large scale testing which will be presented are to (1) improve understanding of the behaviour of this common type of structure under cyclic inelastic deformations, (2) permit validation and improvement of computer models for predicting global and local response, (3) improve understanding of the relation between system, member and connection behaviour, and (4) assess the adequacy of various guidelines for design and analysis.
Patxi Uriz has obtained his undergraduate degree (Bachelors of Science) from the University of California, Berkeley in December of 1999. Patxi then worked as a design engineer for Degenkolb Engineers in San Francisco, California for close to one year before returning to graduate school in the Structural Engineering, Mechanics, and Materials program at the University of California, Berkeley. Patxi completed his Masters of Science degree in 2001, and is now in the final stages of preparing his doctoral dissertation for the degree of doctorate of philosophy (Ph.D.). Patxi has devoted most of his research in the area of understanding the design, behavior, and hazards of concentrically braced steel structures. His chief contributions to this topic are in analytical modeling of braces including the effects of low cycle fatigue. Patxi plans to work in industry with a specialization in structural forensics.
Reference
Prof. Guillermo Rus Carlborg. Dpt. Structure Mechanics
Tel: 958 249 482 E-mail. grus@ugr.es
