Study On Mechanical Characteristics In The Cable-Beam Anchorage Zones Of Tensile Anchor Plate Of Long-span Railway Cable-stayed Bridge

The cable-girder anchorage of the cable-stayed bridge is an important part of connection of stay cable and beam.Under the long-term load,there are some problems,such as large transmission load,complicated mechanism of force transmission and local stress concentration.The new Yuekou Hanjiang Bridge is one of the few applications of tensile anchor plate of cable-girder anchorage of railway cable-stayed bridge,its edge of the web is directly stretched out the roof 15cm,and the tensile anchor plate is directly welded with its butt.Based on the new type of tensile anchor plate of Hanjiang Bridge,this is carried on the thorough research to it,and the main research contents and results are as follows:1.The finite element simulation analysis is carried out on the cable-beam anchorage zones of tensile anchor plate.Through a variety of unit combinations of methods to verify each other,in the end,it is concluded that the combination of shell element and solid element is more reasonable to build tensile anchor plate.2.The 3D finite element analysis of the cable-beam anchorage zones of tensile anchor plate of Yuekou Hanjiang Bridge is carried out,this is analyzed the cable-beam anchorage zones,the stress value and the distribution regularity of the cable-beam anchorage zones of tensile anchor plate under the most agile force,and analyzes the stress variation tendency of the main load-transfer weld seam of the tensile anchor plate,and proposes some measures to improve the stress distribution and reduce the stress concentration phenomenon.3.Based on the principle of stress equivalence,the experimental model of the cable-beam anchorage zones of tensile anchor plate of Yuekou Hanjiang Bridge is designed.Through the finite element analysis and calculation,comparing the different design scheme,the scheme three is finally taken as the fatigue test model.The calculation results of the plate parts of the tensile anchor plate of the test model are compared with the calculated results of the anchor plates of the original bridge model,and the rationality and feasibility of the fatigue test model are determined.4.On the basis of simulation analysis,the model test of tensile anchor plate is carried out.According to the test results,it is found that the experimental data of the main plates of tensile anchor plate are consistent with the results of the finite element simulation analysis,and the finite element numerical analysis is effective for the local stress analysis of the bridge structure.In the fatigue validation phase,each measuring point is in a flexible working state,the tensile anchor plate does not appear cracks;in fatigue failure stage,the test values of the model points are basically unchanged with the increase of load cycle times,and the stress regularity of each point of the model is basically the same as the fatigue validation phase.Finally,the cracks are not found by sampling and grinding the model structure.Therefore,the tensile anchor plate of the Hanjiang Bridge has sufficient fatigue strength reserves.