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Mathematical Problems in Engineering
Volume 2016, Article ID 8024043, 11 pages
http://dx.doi.org/10.1155/2016/8024043
Research Article

Buckling Instability Behavior of Steel Bridge under Fire Hazard

Hubei Key Laboratory of Roadway Bridge & Structure Engineering, Wuhan University of Technology, Wuhan 430070, China

Received 28 December 2015; Accepted 24 March 2016

Academic Editor: Veljko Milutinovic

Copyright © 2016 Ying Wang and Muyu Liu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Failure of buckling instability will most likely occur before the displacement reaches the allowable value of the code when a tanker burns under the steel bridge. This research focuses on critical buckling stress of bridge under fire hazard and a thermal analysis model of a steel bridge is established by FDS (Fire Dynamics Simulator). Thermal parameters of the steel are determined by the polynomial fitting method. Temperature field and elastic modulus of the bridge changing with time are calculated by determining the heat release rate function of tanker. Critical buckling stress of the bridge web and bottom floor changing with time is calculated according to steel floor buckling theory. Finite element software ANSYS is used to verify the result. Results show that when a tanker is burning for 17 minutes, critical buckling stress of steel web will be reduced to = 19.1 MPa and = 38.8 MPa, which is less than the web stress ( = 19.6 MPa, = 39.8 MPa) caused by dead and live load. So steel web will be the first to show shear flexural bending buckling failure. Displacement in the midspan will reach 35.4 mm at this time, which was less than the allowable displacement (50 mm) set by standard. The best rescue time of the bridge under fire hazard is within 15 minutes.