2002 TMS Annual Meeting & Exhibition: Special Session on the World Trade Center Collapse

February 17–21 · 2002 TMS ANNUAL MEETING · Seattle, Washington




Wednesday, February 20, 2002 2:00 pm

Room 611, Washington State Convention & Trade Center

Session Chair:
Toni Grobstein Maréchaux, National Materials Advisory Board, Washington, DC

An exciting and timely presentation of invited presentations beginning with the question - Why?

But, focusing on the structural materials answers and innovations that can minimize the chances of a reoccurrence of the September 11th disaster and generally improve the performance of existing and new structural building materials. The construction industry uses larger volumes of material than any other, and is a $40 trillion per year business worldwide. New technologies for better, more fire resistant, and more cost effective structures are a tremendous opportunity for materials science.

Featuring the following presentations:

2:00 PM     Opening Remarks
2:10 PM Why Did the World Trade Center Collapse? Science, Engineering, and Speculation
Presenter: Christopher Musso, Massachusetts Institute of Technology, Cambridge, Massachusetts

There have been numerous reports detailing the cause of the World Trade Center collapse on September 11, 2001. Most have provided qualitative explanations. However, simple quantitative analyses show that some common conclusions are incorrect. For example, steel could not have melted in the Tower fires and there was more structural damage than simple softening of the steel at elevated temperatures. Some guidelines for improvements in future structures will be presented.
2:50 PM

New Materials for Building Structures?
Presenter: John Hooper, Skilling Ward Magnusson Barkshire, Seattle, Washington

Although new materials are being introduced into building structures, their introduction is slowed by many factors including cost and the code approval process. Our "new materials", generally, relate to finding new ways to use familiar materials. Advances in analysis tools and methodologies has allowed this opportunity to extend the envelope and geometric application of traditional materials such as steel, timber and concrete as well as developing new concepts for nonstructural items such as curtain walls and stairs. Applications of these advances will be presented with additional discussion regarding the next generation. Research is underway that, over time, will allow for carbon, kevlar, mylar and other composites to enter building structure mainstream. Some examples of these opportunities will be presented along with an estimated timetable for use.

3:30 PM Break
3:40 PM

A Structural Engineer's Dream for Ideal Post 9/11 Construction Materials
Presenter: Loring A. Wyllie, Jr., Degenkolb Engineers, San Francisco, California

A Structural Engineer uses existing construction materials to design many large, complex structures that will provide safety to occupants. Connections must be adequate and designs should consider extraordinary conditions such as strong winds and earthquakes. With the recent wave of terrorist attacks there is a desire to toughen our structures to improve their performance under extreme and unexpected loadings. While some improved structural details will help, better materials would significantly improve performance for these unexpected conditions. This presentation will focus on some of the material properties that Structural Engineers would consider ideal for survival under extreme conditions. Normally, material changes are relatively minor and focus on higher strength, improved chemistry to facilitate connections, or improved ductility. Rather than trying to make minor changes to existing materials, the speaker will step back and dream of new materials that would significantly improve our built environment for the unexpected loadings and conditions, which may occur.

4:20 PM

Virtual Materials and Service Life Design
Presenter: Geoffrey Frohnsdorff, National Institute of Standards and Technology, Gaithersburg, Maryland

The designer of a building, or other constructed asset, must exercise many judgments in ensuring that the intended life will be achieved without large unforeseen expenses. The generally satisfactory performance of buildings attests to the generally good judgment of designers. However, enough durability problems occur to suggest that more needs to be done to help ensure achievement of the intended service life at a reasonable life-cycle cost. Possibilities for increasing the likelihood of satisfactory long-term performance are: 1) establishing service life design standards, 2) providing reliable and realistic accelerated tests and models for predicting long-term behavior of materials and components, and 3) providing convenient access to reliable, easily-usable knowledge about the long-term performance of materials and components.

If you are at all interested in the facts surrounding the materials failures contributing to the World Trade Center collapse, or your professional focus is on the design, testing, and application of structural materials, don't miss this important presentation by some of the top materials and structural engineers in the field.


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