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The Collapse of the World Trade Center Twin Towers: A Metallurgist's View



Frank W. Gayle


The National Institute of Standards and Technology (NIST) has completed its four-year investigation of the World Trade Center disaster. The investigation addressed many aspects of the catastrophe, from occupant egress to factors affecting how long the Twin Towers stood after being hit by the airplanes, with the goal of gaining valuable information for future best practices in building materials and design, and emergency procedures. This article is based on an edited transcript of a presentation given by Frank W. Gayle (NIST) on April 12, 2007, in Symposium X at the Materials Research Society Spring Meeting in San Francisco. The presentation describes the structure of the towers, the analysis of the recovered steel, and special issues faced in the Investigation. In addition, the most probable collapse sequence is presented for each of the towers as concluded in the NIST Investigation.
Mrs Bulletin


failure analysis, finite element model, mechanical properties, structural steel, twin towers, world trade center


Gayle, F. (2008), The Collapse of the World Trade Center Twin Towers: A Metallurgist's View, Mrs Bulletin (Accessed April 16, 2024)
Created October 16, 2008