Research On Fatigue Test Of Composite Box Girder With Corrugated Steel Webs

With the rapid development of the combined bridge in China,especially the wide application of steel concrete composite beam bridge,the composite beam bridge with corrugated steel web has been paid much attention by a new type of composite structure.It replaced the traditional concrete web with corrugated steel web,which fully utilized the characteristics of two materials and reduced the weight of composite beams to a large extent,complying with the development trend of the bridge structure.The new corrugated steel web composite box girder also takes the high-strength flat steel plate instead of the traditional wave steel concrete floor.In order to study the fatigue performance of this new composite structure,the 40 m Span Composite Box Girder with corrugated steel web is used as the prototype.The fatigue performance of the model beam is studied through the fatigue test.The main contents of this paper are as follows:(1)The normal stress,deflection and change law of the concrete roof and the bottom plate of the composite box girder of corrugated steel webs under static loading are studied,and the change regularity of its integrity and stiffness is analyzed.(2)Under the effect of fatigue load,the normal stress,deflection and change law of the concrete roof and the bottom plate of the composite box girder of corrugated steel webs are studied,and the variation of its integrity and stiffness under the fatigue load is analyzed,and its fatigue resistance is obtained.Under the action of fatigue load,the positive stress and change law of the weak point of fatigue strength at the S point weld of the composite box girder of corrugated steel webs are studied to reflect the stiffness and get its fatigue performance.(3)Analysis of the normal stress,deflection and the regular stress of the weak point of fatigue strength at the weld of S points after the completion of the 2 million cyclic loading.(4)Through the finite element numerical simulation,the positive stress of the stress,deflection and the fatigue weak point in the weld near the S point under the load is obtained,and the results are compared with the data obtained from the fatigue test to verify the accuracy of the fatigue test.