Selection Optimization And Stability Design Of Cable Arch Structures

Although systematic design methods for steel arches have been established based on extensive studies,for cable arches investigations are lacking.The optimal selection and ultimate strength prediction are still unsolved.This paper dealt with the structural comparison and optimization of circular cable arch structures,as well as the in-plane and out-of-plane elasto-plastic stability behavior and design of spoke arches.Firstly,two commonly used structural forms namely the cable-stayed arch and the spoke arch were selected and compared.The finite element method was used to analyze the in-plane stability and strength of cable arches with various configurations,considering the geometric and material nonlinearity.The effects of the slenderness ratio,rise-to-span ratio,cable numbers and cable areas were explored and structural indexes such as the ultimate load-bearing capacity,structural stiffness and cable force were used for the configuration optimization.It was concluded that the spoke arch is the optimal cable-arch structural form under various working conditions.Secondly,the in-plane elastoplastic stability performance of the spoke arch was studied considering the effect of prestress.The parametric studies were carried out to fully consider the influence of parameters such as the number of cables,cable area,arch slenderness ratio and rise-span ratio on the ultimate bearing capacity,and an optimized range for theses parameters was proposed.Finally,on the basis of the obtained parameter range,the response surface method was used to propose the formula to predict the inplane elastoplastic bearing capacity of spoke arches.Finally,the out-of-plane elasto-plastic stability of spoke arches was studied.From the view of buckling path as well as internal force and deformation development,the elasto-plastic buckling behaviour of unbraced spoke arches was explored.Next,for the spoke arch with lateral braces,the buckling performance and the threshold bracing stiffness under different bracing conditions were revealed.Finally,a multi-spoke-arch system was established to study the effects of the number of tie rods and the number of spoke arches on the stable bearing capacity of the system.Practical design suggestions were put forward.