Stability Analysis And Optimization Design Of Beam String Structures

There was a rapid development of wide span spatial structure during the past decade in our country, which can be reflected in three aspects: abundant project records, a large variety of structure models and gradual improvement on theory and design. To meet the construction requirements of wide span structure developed since 1990's, pre-stressed techniques were applied to steel spatial structures to create various of new systems. Among these systems, pre-stressed space grid and reticulated shell, cable arch, cable stayed space grid and other cable-strut systems can fully make use of the strength of stressed elements and have light weight and modern design. All these advantages lead to a prosperous prospect for wide span spatial structures.Beam String Structure (BSS) is a typical pre-stressed cable-strut system developed in recent years. It enjoys the advantages of reasonable bearing mechanism system, simple construction process, convenient transportation and modern design. As the application of BSS in our country is still at a preliminary stage, studies on its bearing mechanism will be instructional for practical projects.The stability of BSS can be classified two, one is local stability, and another is global stability. In this paper, components stabilities of BSS are analyzed respectively.In this paper, I take use of APDL (ANSYS Parametric Design Language) in ANSYS, and develop the special parametric program for the model building and solution of the pre-stressed spatial truss string structure. In this paper, the optimizations of section size of BSS are also made by use of optimization tool of ANSYS.As a conclusion, the structure volume in use is studied with changing the rise-to-span ratio, sag ratio as a parameter.