I attach an essay we wrote for a book that will be published by University of Minnesota Press titled "The city, the river, the bridge." The essay is a transcription of part of a public lecture I gave on infrastructure and on the bridge collapse.

After the bridge collapse there were several posts on Imechanica that included speculation about the cause of the collapse, including fatigue crack growth, lack of redundancy, etc.. Our investigation determined the collapse was a result of an undersized gusset plate that reached its plastic limit load. 

Dear collegues,

Starting with a few questions which I asked in my introductory class 30 years ago at UC Davis, and which were never answered, I found enough reasons over the years to reject the current theory of elasticity, stress and continuum mechanics entirely.

2009 SIMULIA Customer Conference

May 18-21, 2009 • the Brewery, London, England

Micromechanics---loosely speaking, is the study of heterogeneities in materials and its consequences for material or continuum behavior. This encompasses studies of inclusions, dislocations, cracks or more generally defects. A related problem is that of "coarse-graining" or in other words the effective homogenized properties of a heterogeneous material. The latter is a recurring theme in all of physical sciences not just solid mechanics. Micromechanics, a formidable subject by all means, dominated a substantial part of the history of solid mechanics. Several of our Timoshenko awardees have been associated with this subject, e.g. Eshelby, Hill, Keller, Irwin, Rice among others.

A new $150M Research Center of Excellence (RCE) on Mechanobiology has been set up at the National University of Singapore  (http://newshub.nus.edu.sg/headlines/0209/TRCE_20Feb09.php).