Experimental Study On Fatigue Performance Of Tensile Anchor Plate Of Cable Stayed Bridge

As an important part of cable force transmission of cable stayed bridge, Cable girder anchorage structure has many characteristics, for example the number of plates is large, the manufacture process is complex, the welds is centralized and so on. And it is the key part of the structure design of cable stayed bridge. With the rapid development of long span steel cable stayed bridge, it put forward a higher request to the anchorage structure of the cable and the steel girder. Among the several types of anchor of cable and girder in the steel- concrete cable stayed bridge, there are four common models, which are steel anchor-pipe, anchor-box, auricular anchor plate, tensile anchor plate. In recent years, tensile anchor plate is more and more used in the construction of the bridge in our country.Under the background of tensil anchor plate of Wujiang bridge, this paper refers to relevant design specification and related research in China, and uses the finite element analysis and full scale fatigue test, then makes some research work:(1) Finite element analysis of Wujiang bri dge was made, and anchorage structure correspond to M14 cable was made sure for the object of the study. Reference to domestic and foreign relevant standards and domestic related research methods, the fatigue load of full scale fatigue test was determined. Then the influence of the mean stress was considered, and the upper and lower peak value of fatigue load were determined.(2) Based on experiment similar theory, and compared with finite element calculation results of bridge segment, then by the repeated calculations, this paper determined the design details of full-scale model. According to the size and the requirements of test model, this paper designed the fatigue test plan. After 3 million times loading cycles, the test showed that: fatigue cracks were not found in the full-scale model, and the stress test results were in good agreement with the finite element structure, the structure was in the elastic state and the performance under the force had not declined.(3) Reference to relevant design specifications at home and abroad, this paper thinks that the fatigue performance of the anchor plate meets the requirements of fatigue design. Based on guaranteeing the welding quality, production process requirements and normal maintenance, the probability of fa tigue failure of the anchor plate structure of Wujiang bridge in the design life is very small.(4) Acorrding to analysis of the anchor plate form of Wujiang bridge, it shows that: the first and second welds are mainly to bear the shear stress, and the fro nt section of the weld is more efficient, the former 0.3L bears about 50% of the shear; The butt weld mainly bears the tensile stress and shear stress, and the distribution is mean; The increase of the thickness of the anchor plate and the stiffened plate has a certain decrease on the stress level of the anchor plate; the increase of the thickness of the steel girder web is helpful to reduce the stress level of the butt weld, but the effect is gradually decreasing; by making the stiffened plate cross the bu tt weld, it is helpful to increase the transverse stiffness of the anchor plate, enhance the ability to resist surface deformation, reduce the stress level of the butt weld.