Mechanical Property Study Of Cable Dome Structure Considering Bending Stiffness Of Cables

The steel cable is a key component of the pre-stressed steel structure.In the previous structural design,only its tensile properties were considered,but the bending performance was negligible.However,with the continuous increase in the size of the structure,the diameter of the cables is also increasing.Therefore,the effect of the bending resistance of the steel cable on the mechanical characteristics of the structure becomes non-negligible,and the effect of cable bending stiffness should be further considered in the structural design.Based on the above considerations,this paper carried out the experimental study of the bending stiffness of steel cables,the static and dynamic test of the Rigid Bracing Dome and Conventional Cable Dome,and the ultimate bearing capacity simulation analysis,and obtained the following research results:?1?The range of bending stiffness of Galfan cables and stainless steel cables is given by testing the flexural rigidity of steel cables.Using the frequency method to test the bending stiffness of steel cables,determine the natural vibration characteristics of steel cables with different diameters,and calculate the bending stiffness of these cables,and finally determine the relationship between the actual bending stiffness and diameters of steel cables.The final result shows that the actual bending stiffness of the cables is?0.37-0.54?EI_max.?2?The static performance difference of the Rigid Bracing Dome and the Conventional Cable Dome structure is obtained through the static performance comparison test.A 6m-diameter Levy Rigid Bracing Dome and Conventional Cable Dome test model were designed,and static test was conducted on them.Comparing the test results,the differences in the static performance of the two structures under static load were determined.The experimental results show that the internal forces of the two structures have the same tendency,and the vertical stiffness of the Rigid Bracing Dome structure is obviously better than that of the Conventional Cable Dome structure.?3?Through the comparative study of dynamic characteristics,the modal performance differences between the Rigid Bracing Dome and the Conventional Cable Dome were obtained.The dynamic characteristics of the Levy Rigid Bracing Dome and Conventional Cable Dome test model were tested by the exciter vibration method,and the natural vibration characteristics were measured.Simultaneously using the measured bending stiffness of the steel cables,the finite element calculation software ABAQUS was used to perform finite element numerical simulations on the two models.Comparing the experimental results with the numerical simulation results,the differences in the natural vibration characteristics of the two structures under dynamic action were found.The results show that the test results are in good agreement with the theoretical results,and that the natural vibration frequencies are in the same trend.The load action will change the stiffness distribution of the structure,but the effect of the external load is not completely equivalent to the increase of the structural quality.The load have a complex effect on stiffness of the structure.In the same pre-stressed state,the rigidity of the Rigid Bracing Dome structure is greater than that of the Conventional Cable Dome structure.?4?Through the simulation analysis of ultimate bearing capacity,the influence law of the ultimate bearing capacity of steel cable bending stiffness is obtained.The cooling method was used to increase the initial prestress of the Levy Rigid Bracing Dome and Conventional Cable Dome finite element model,Considering the influence of the bending stiffness on the extreme stress of the steel wire on the outer ring of the circle cable,the ultimate bearing capacity of the Rigid Bracing Dome and the Conventional Cable Dome in the conditions of low stress and high stress is simulated and analyzed.The results show that in the prestress design process,the stress safety margin of the outer loop cables should be as much as twice the prestress of the inside ridge cables,so that the outer loop cables?rods?can reach the ultimate tensile stress at the same time when the inside ridge cables fails.