Recent Advances in Fire: Structure Analysis.
Recent Advances in Fire: Structure Analysis.
(1871 K)
Duthinh, D.; McGrattan, K. B.; Khashkia, A.
Fire Safety Journal, Vol. 43, No. 2, 161-167, February
2008.
Keywords:
World Trade Center; structural systems; surface
temperature; deflection; insulation; thermometers;
structural analysis; thermal analysis; building
collapse; equations; computer programs; fire tests; ASTM
E 119; experiments; temperature
Abstract:
One of the recommendations of the National Construction
Safety Team (NCST) for the Federal Building and Fire
Safety Investigation of the World Trade Center Disaster
[NIST NCSTAR 1 Final report on the collapse of the World
Trade Center Towers. NCST for the Federal Building and
Fire Safety Investigation of the World Trade Center
Disaster, National Institute of Standards and
Technology, Gaithersburg, MD, September 2005] is to
enhance the capability of available computational
software to predict the effects of fires in buildings,
for use in the design of fire protection systems and the
analysis of building response to fires. Following this
recommendation, this paper presents two new interfaces
in fire-thermal-structural analysis. The first interface
uses adiabatic surface temperatures to provide an
efficient way of transferring thermal results from a
fire simulation to a thermal analysis. It assigns these
temperatures to surface elements of structural members
based on proximity and directionality. The second
interface allows the transfer of temperature results
from a thermal analysis modeled with solid elements to a
structural analysis modeled with beams and shells. The
interface also allows the reverse, namely the geometric
updating of the thermal model with deflections and
strains obtained from the structural analysis. This last
step is particularly useful in intense fires of long
duration, where significant deflections and strains
could cause damage to insulation and displace the
structure to a different thermal regime. The procedures
can be used for a variety of fire simulation, thermal,
and structural analysis software.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899