Research For Stability Of Spatial Arch-Reticulated Shell Hybrid Steel Structures

Arch-reticulated shell hybrid structure is a new type structure systemoptimized by arch and latticed shell. As it synthesizes the advantages of botharch and latticed shell, it can increase the structure span and the economicbenefit to some extent. As single structure systems, arch and latticed shellalways have stability problems, which may become the controlling factors instructure design, and so far there has been deep research on these kinds ofproblems, while the mechanical performance of this kind of hybrid structurehas not been studied systematically. Thus it is very necessary to study thestability of arch-reticulated shell hybrid steel structures.This paper studies the global stability of arch-reticulated hybrid steelstructure by finite element methods systematically, including stabilityanalyses, parametric analyses, simiplified calculation, anti-progressivecollapse analyses and dynamic stability analyses. The main results are asfollowing:(1) The calculation method and judging standard are proposed, that is theelasto-plastic full-range analysis considerring geometric imperfection must beconducted, and when the obtaining stability factors meet the rules set in thispaper with siginificant global bucking modes, the stability can be consideredto meet requirements.(2) The concept of arch-reticulated shell stiffness ratio is proposed, andits vital effect on the stability is verified. Meanwhile, temperature load haveadverse effect on the stability, so it should also be considered in structuredesign.(3) A simplified calculation method of the stability of arch-reticulated shellhybrid structure is proposed, that is to analyze the stability of the single arch whichhas the largest span in the whole structure. It is regulated that when the elaso-plastic stability factor obtained by the procedures in this paper is greater than2.0, thestability of the whole structure can be considered to meet requirements.(4) The anti-progressive collapse performance of arch-reticulated hybridstructure is verified. When the initial broken modes set in this paper happens,the broken range is limited in the local latticed shell regions among arches,and the structure won’t collapse progressively. When there are cables in thestructure, the prestressed value of cables will have significant effect on thewhole structure’s load bearing behavior. When some of them break up, thelocal mechanical performace may change, and thus it will affect the wholestructure’s anti-progresive collapse behavior.(5) The judging standard of dynamic stability of arch-reticaulated hybridstructure under earthquake is proposed, that is to judge whether the structurewill buckle under the corresponding earthquake according to the peakacceleration provided in the specification after obtaining the critical peakacceleration by time-history analyses.