The Research Of Fatigue Stress Characteristics Of U Rib Arc Incision Of Orthotropic Steel Bridge Deck

At present, the suspension bridge and cable-stayed bridge is the main bridge of long-span Bridges, steel box girder is the most important of long-span bridge deck structure system. Now most of the steel box girder is orthotropic steel bridge deck structure, orthotropic steel bridge deck is made between longitudinal and transverse vertical stiffener, and along with the bridge panel composed of the overall structure of the wheel loads together. It has a series of advantages, such as light weight, with makings provinces, ultimate bearing capacity big, short construction period, so, today the structure form of bridge deck structure often as part of the steel box girder is widely used in the construction of the long-span bridges. With the rapid development of expressway and high-speed railway construction in China, the orthotropic steel bridge panel due to its superior structure in highway Bridges and used widely in the construction of railway Bridges. But the orthotropic steel bridge panel stress is complex, and its structure form continuous improvement and development, at the same time, the stress concentration and the appearance of weld defects are prone to fatigue damage, such as bridge panel under all kinds of vehicle load repeated action will cause cumulative damage; Steel bridge panel for directly inherit the local effect of the vehicle, and the stress influence line is short, driving a car can cause several times after the stress cycle, plus the welds and welding defects of the stress concentration of the steel bridge fatigue cracking panel is easy to occur. So the fatigue of the orthotropic steel bridge panel has long been a key problem in highway Bridges and railway bridge. Some of the earlier application of steel bridge deck in the world countries such as Japan, Germany, France, the UK has been found in the current operation of the real bridge fatigue crack. Researchers around the world for steel bridge fatigue damage examples to carry on the extensive research, the results show that the steel bridge especially fatigue and checking calculation of orthotropic steel bridge deck is a critical task. It contains the orthotropic steel bridge panel stress calculation, structure analysis, fatigue strength and fatigue calculation method and the core problems such as vehicle load spectrum.This article uses the ANSYS large general finite element software for steel box girder on the numerical simulations of the orthotropic steel bridge panel, the arc incision shape, thickness of top plate, the thickness of the diaphragm plate was analyzed, and the key parameters, such as the horizontal clapboard and U rib weld junction of stress state. Results show that the shape of the through hole of stress significantly, the influence of the roof of a smaller influence on the stress of the weld corner of diaphragm plate thickness has bigger influence on the fatigue crack. Right through to the end hole welding and welding hole edge stress distribution analysis, by means of the criterion of Miner linear cumulative damage, to calculate the equivalent stress amplitude of each focus by comparing found that for the end hole welding, road than standard railway standard equivalent stress amplitude is large; For welding hole weld edge, is just the opposite. In addition, this article through to the end of the hole welding stress concentration phenomenon took measures, through the optimized the structure of the welding holes can effectively alleviate the severe stress concentration.