Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Experiments and Modeling of Structural Steel Elements Exposed to Fire. Federal Building and Fire Safety Investigation of the World Trade Center Disaster (NIST NCSTAR 1-5B)



Anthony P. Hamins, Alexander Maranghides, Kevin B. McGrattan, Erik L. Johnsson, Thomas J. Ohlemiller, Michelle K. Donnelly, Jiann C. Yang, George W. Mulholland, Kuldeep R. Prasad, S R. Kukuck, Robert Anleitner, Therese P. McAllister


Reconstructing the fires and their impact on structural components in the World Trade Center (WTC) buildings on September 11, 2001, requires extensive use of computational models. For the use of such models to be a viable investigative tool, it is essential to know the accuracy with which they capture the physical phenomena of the fires and the concurrent heat transfer to the building structure. This report documents a series of large-scale experiments that was conducted in the National Institute of Standards and Technology (NIST) Large Fire Laboratory from March 10 to March 26, 2003. The experiments represent one phase of an effort to ascertain the validity of the models for the NIST WTC Investigation. The objective of the experiments was to assess the accuracy with which (1) the NIST Fire Dynamics Simulator (FDS) fire model predicts the thermal environment in a burning compartment and (2) the NIST Fire Structure Interface (FSI) model in combination with the ANSYS finite-element model predicts the temperature rise of structural steel components in a burning compartment. The experiments also had the potential to improve input parameters in the modeling, if appropriate, and, in general, help to increase understanding of the sequence of events that occurred in the WTC tower fires....
National Construction Safety Team Act Reports (NIST NCSTAR) - 1-5
Report Number


World Trade Center, high rise buildings, building collapse, disasters, fire safety, fire investigations, terrorists, terrorism, experiments, steel structures, fire models, velocity measurements, heat flux, thermocouples, temperature, steels
Created September 1, 2005, Updated February 19, 2017