Mechanical Properties And Stability Analysis Of Beam String Structure Based On Energy Principle

Beam String Structure (BSS) is a new type of large-span prestressed spatialstructure, which is developing rapidly in recent years, due to its simple geometrystructure and power flow transfer clear, are gotten the favour of the engineering designpersonnel and widely used in the convention and exhibition center, exhibition halls,railway stations, and other important public buildings.Mathematic, mechanics andcalculation analysis techniques are synthetically applied into theoretical analysis andnumerical calculation of mechanical properties and stable performance of BSS in thispaper.The main contents in this dissertation are as follows:(1) Based on the energy variation principles, the static theory analysis model ofhinge, horizontal elastic support and simply supported three kinds of boundaryconditions BSS is established, analytical expressions for the internalforce anddisplacement of the structure are achieved, which are applicable to many common loadcases, including pretension load, all cross distributed load, half cross distributed load,temperature load. The static behavior of the structure under differentboundaryconditons is analyzed according to the theoretical expressions.(2) Based on the energy variation principles, the nonlinear stability equilibriumequations for hinge and horizontal elastic support BSS are established，and thenanti-symmetric bifurcation buckling stability load are proposed. According to thetheory of elastic, the theoretical analysis of load distribution and internal force transferpath to simply supported BSS, due to the effect of the vertical of the poles and function of system self balancing, there exists no problem of the first kind of stability.(3) Numerical method is applied to the whole process analysis of elastic-plasticapacity, failure mechanism of instability is discussed under all cross distributed loadand half cross distributed load. The calculation formulas of elastic-plastic limit load arededuced under all cross distributed load and half cross distributed load.(4) By using energy method, the potential energy equation of BSS is establishedand principle of stationary potential enery is used to investigate the out-of-plane elasticbucking load of out-of-plane unbraced BSS which is under uniformoly distributed load.And then the out-of-plane elastic-plastic stability is studied, the changes of variousparameters on the effect on the stability of the out-of-plane elastoplastic are discussed.(5) The numerical analysis of out-of-plane stability on out-of-plane braced BSS isstudied to reveals the characteristics of the elastic buckling.Influence of lateral supportstiffness, support restraint, brace strut connections and rise span ratio on out-of-planeof BSS are studied systemically.(6) Starting from structural design factors, according to the mechanicalcharacteristics of Beam String Structure and lasso and wind-up beam material limitstrength condition, pushed the span limit formula of plane BSS, and the limit span ofplanar BSS influencing factors are analyzed.