Damage and Collapse Assessment in Steel and Composite Structures
Jerome F. Hajjar, Ph.D., P.E.
CDM Smith Professor and Chair
Department of Civil and Environmental Engineering
Wednesday, October 11, 4 p.m., Kearney 112
Free and open to the public. Reception to follow.
This presentation will highlight recent work on assessment of damage and collapse in steel and composite steel/concrete structures. Collapse of a structural system is often documented in seismic engineering through the use of incremental dynamic analysis, in which various metrics are used to document collapse indirectly, e.g., through observing a large increase in interstory drift in a structure relative to a small increase in the peak spectral acceleration of the ground motion. The presentation begins by discussing collapse prediction and associated validation of seismic performance factors for composite frame structures in conjunction with current AISC and ASCE seismic provisions. The presentation then highlights a new approach for predicting the collapse of structures through the use of element deletion strategies in finite element analysis, validated against a broad range of experiments of steel structures experiencing various types of damage leading to collapse. An energy-based collapse criterion is then introduced that provides a new platform for predicting collapse in seismic analysis. This criterion is proposed to form the basis for developing collapse fragility models and for redefining collapse assessment within incremental dynamic analysis.
Jerry Hajjar is CDM Smith Professor and Chair of the Department of Civil and Environmental Engineering at Northeastern University. He has served as Chair of the Structures Faculty and as Deputy Director of the NSF Mid-America Earthquake Center at the University of Illinois at Urbana-Champaign, and was a professor at the University of Minnesota and an Associate at Skidmore Owings & Merrill. Jerry serves on AISC’s Committee on Specifications and chairs Task Committee 5 on Composite Construction; he is a member of the SEI Technical Activities Division Executive Committee; and he was the 2004-2005 ASCE Minnesota Section President. Dr. Hajjar was made a Fellow of SEI in 2013 and of ASCE in 2007, and was awarded the 2016 ASCE Moisseiff Award, the 2015 BSCES Clemens Herschel Award, the 2010 Popular Mechanics Breakthrough Award, the 2009 ASCE Shortridge Hardesty Award, the 2005 AISC T. R. Higgins Lectureship Award, the 2004 AISC Special Achievement Award, the 2003 ASCE Walter L. Huber Civil Engineering Research Prize, and the 2000 ASCE Norman Medal for his research on steel and composite structures, structural stability, and earthquake engineering. He has also won several teaching awards. Dr. Hajjar is a registered professional engineer in Illinois and Minnesota.
About the series
The Edwards Lecture Series, initiated by Professor Harry Yeh in 2005, is named in honor of Miles Lowell Edwards – an engineering genius – known for his unique and successful inventions. His remarkable achievements included developing prosthetic heart valves, creating timber industry materials to debark trees, and enabling Boeing B-17 aircraft pumps to operate at high altitudes.
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- 2007: Chiang C. Mei, “Nonlinear Resonance in a Harbor”
- 2008: Jim Duncan Smith, “Flow, Sediment Transport, and Geomorphic Adjustment in Rivers”
- 2009: Robert Guza, “Observations of Southern California Waves and Wave-Driven Processes”
- 2010: Gary Parker, “Self-Stratification due to Suspended Sediment in Rivers and Turbidity Currents: the Delicate Balance of the Latter”
- 2011: Peter Rhines, “Exploring the Subpolar Oceans with Seagliders and Satellite Altimetry”
- 2013: Greg Lawrence, “Waves and Currents: Hawking Radiation in the Hydraulics Laboratory”
- 2014: Brian Kirby, “Geometrically Enhanced Differential Immunocapture: Using Obstacle Arrays in Microfluidic Devices to Enhance Efficient and Pure Rare Cell Capture from Fluid Suspensions”
- 2015: Juan Restrepo, “Taking Uncertainties into Account in Geosciences, Physics, and Engineering”
- 2016: Thomas E. Boothby, "Engineering Iron and Stone"
- 2017: Gregory G. Deierlein, "From Performance-Based Engineering to Earthquake Resilience"
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