Coupled Thermal-Elastic Response of Structures to Fires.
Coupled Thermal-Elastic Response of Structures to Fires.
(85 K)
Prasad, K. R.; Baum, H. R.
Poster Session V and Reception;
Combustion Institute/Western States, Central States and
Eastern States. Fourth (4th) Joint Meeting of the U.S.
Sections. Hosted by The Eastern States Section of the
Combustion Institute and Drexel University. Poster
Session V and Reception. March 20-23, 2005,
Philadelphia, PA, 1-6 pp, 2005.
Keywords:
combustion; structures; equaitons; temperature; stress
(mechanics); thermoelasiticity; temperature field
Abstract:
There has been a resurgence of interest in the response
of building structures to fires over the past several
years. This interest was greatly enhanced by the attack
on, and subsequent collapse of, theWorld Trade Center
(WTC) towers. Traditional methods of modeling this
behavior are based on computing the thermal response of
an un-deformed structure and performing structural
analysis in a sequential manner. This procedure can lead
to significant errors in the thermally induced
structural response. While the applications of interest
clearly involve highly non-linear calculations, the
starting point for most fire scenarios is almost always
an undamaged building at room temperature. Since
virtually all buildings are designed to keep the
stresses well below the elastic limit and the
deflections of the load bearing structure reasonably
small, the starting point for simulations of fire
induced damage must lie within the domain of linear
elasticity. Moreover, the difficulties that arise are
evident before the temperature rise is large enough to
affect the elastic or thermal properties of most
structural materials. Under these circumstances the
thermally induced stresses are also linear, and the
temperature fields can be described by the heat
conduction equation for the material(s) of interest.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899