New paper: “Some Misunderstandings Related to WTC Collapse Analysis”

July 17th, 2013 Posted in

Some Misunderstandings Related to WTC Collapse Analysis

Gregory Szuladzinski*, Anthony Szamboti and Richard Johns
1-FIEAust, Analytical Service Pty Ltd, Northbridge 2063, Australia 2-Mechanical engineer, aerospace industry performing structural and thermal analyses and design 3-Langara College, Vancouver, B.C. Canada. and
Received on 22 Dec 2012, Accepted on 8 March 2013

International Journal of Protective Structures – Volume 4 · Number 2 · 2013

ABSTRACT This article elaborates on variables associated with the collapse of the North Tower of the World Trade Center. The previously published quantifications of inertia, column capacity, and the assumptions related to the beginning of downward motion, are examined and corrected. The reasons for false conclusions reached in several previous analyses are presented.
Key words: Large Deflections, Plasticity, Collapse

1. INTRODUCTION This presentation is not so much about how the WTC towers failed, but about how they could not fail. The objective is to eliminate erroneous concepts supported by false assumptions and by the use of incorrect values for velocity, mass, and column resistance. The only complete hypothesis of the global collapse mechanism of the Towers is a successive flattening of stories associated with compressive column failure and referred to as a Progressive Column Failure mode or PCF in brief. (In the past this mode was often referred to as pancaking, but this term is not used here to avoid ambiguities). It is explained here why PCF could not be the mode of the ultimate destruction. The previously published material is quoted and the new points are brought up. Appendix C can be of interest to those who want a broader description of facts associated with the collapse. The available information relating to the kinetics of the collapse is summarized first.

For discussion, see:

NOTE: The publisher will release the paper for free use on Jan. 1, 2014 and there is currently an 18 GBP ($27.00 USD) copy fee charged for those without a subscription to the journal. However, copies can be sent to individuals for personal use by the authors and anyone they send it to. If you would like a copy, please send a request via:

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