Study On Thermal Response And Fatigue Performance Of Box Girder With Corrugated Steel Webs

Thermal response and fatigue performance are both important aspects that must be found during bridge design. This article is based on the equilibrium theoretic of heat exchange and considered the box girder section under changing heat flow in the time-history analysis method which is developed to calculate the stress field under different temperatures. Use finite element program for bridge fatigue characteristics analyze, in-depth research has been carried out on the following aspects.This article takes the bridge across Feng Hua River of NingBo as there search background. Adopting two dimensional finite element method which is used to analyze the change of bridge’s temperature field in July, analyze the characteristic of temperature distribution in the top Plate, base Plate, webs of typical section at different time as well as the temperature change of various Plates, outside surface, central surface and inside surface. By importing the calculated temperature field numerical calculation for the temperature effect of the bridge analysis the distribution characteristics of temperature stress. To adopt standard temperature gradient calculation results compared with the finite element results analysis, regulating that when only consider temperature stress of top concrete plate can use the standard temperature field data.The software MIDAS/FEA was used to build a refined finite element model of the box girder with corrugated steel webs of Feng Hua River Bridge. And in accordance with the fatigue load spectrum of the vehicle loads during the bridge’s operational phase was determined according to the British Standard BS5400and the Literature method. Finally, according to the classical stress-fatigue life assessment methods, the bridge’s fatigue performance of the vulnerable points on steel web during the bridge’s operational phase was evaluated. From the calculation results, the each position’s cumulative fatigue damage of the box girder with corrugated steel webs bridge of Feng Hua River Bridge during the100-year design reference period were far less than1degree under the action of the standard fatigue car. The fatigue damage on shear key is located in the hole between the inclined plane and the vertical plane of webs, but it will not appear during the design reference period. So we can think of the bridge during the design of the operational phase will not appear fatigue damage.