Analysis And Experimental Research On Fatigue Performance Of Anchor Plate Based On TCD

With the wide application of long-span steel cable-stayed bridges,the cable tension of the cable-stayed gradually increased.Under the effect of huge cable forces,the cable girder anchorage structure of the cable-stayed bridges will be greatly challenged.In addition,the repeated changes in cable force may cause fatigue damage in the stress-concentration part of the anchorage structure of the cable.During the design process,as far as possible,ensure a smooth transition so as not to generate a large stress.Otherwise,under long-term repeated loading,the cable girder anchorage structure is prone to fatigue failure.Therefore,in cable-stayed bridges,the cable girder anchorage structure of is an important force component.It is of great significance to study the fatigue performance of cable girder anchorage structure of cable-stayed bridges for the safety of the entire bridge.This paper uses the cable girder anchorage structure on the cable-stayed bridge of the West Extension line of Dalian southern Binhai Avenue as the background,based on the fatigue model test and finite element analysis based on the critical distance theory,the fatigue performance of the anchorage plate of the cable-stayed bridge was analyzed.Finally,the structure details were fatigue-checked with relevant specifications.The main contents of this article are:(1)The overall finite element analysis was performed on the cable-stayed bridge of the Dalian southern Binhai Avenue West Extension line,and according to the stress and stress amplitudes of the cables,the 316 most likely to be damaged in the cable girder anchorage structure corresponding to each cable is determined.The cable girder anchorage structure is the object of study.(2)Based on the model similarity theory,the detailed design of the fatigue test model is determined,and the process of model making and model installation is introduced.According to the similar requirements of the model and the considering the average stress,the final fatigue test loading scheme is determined.In combination with the influence of the average stress,the upper peak and lower peak of the fatigue load amplitude are determined.The model is subjected to fatigue loading and static loading,and strain and displacement test programs are designed.(3)The results of 2 million fatigue tests have proved that the anchor plate can work in a flexible working state during the loading process,and no large deformation and fatigue failure occurs.Referring to the type of fatigue details in the “Code for Design of Highway Steel Bridges”(JTG D64-2015),it is finally proved that there is a transition between the anchor plate and the anchor pipe joint weld,between the stiffened plate and the anchor plate,between the top plate and the anchor plate.The butt welds and fillet welds do not suffer from fatigue cracking when the construction quality and maintenance are properly maintained.(4)Based on the critical distance theory(TCD),the finite element analysis of the anchor plate was performed,and the fatigue strength of the anchor plate was predicted based on the “line method”.Finally,the equivalent stress amplitude was 141 Mpa,compared with the fatigue limit of the specimen of 420 Mpa,there is a large difference,so no fatigue failure occurs.