Investigations On The Application Of New-Style Buckling Restrained Brace In Structural Engineering

To prevent the buckling of traditional braces in the frame structures, the relatedscholars invented buckling restrained brace in which buckling does not appear. Butbecause of the disadvantages of heavy deadweight and inconveniently to make, abuckling restrained brace can not been applied to the grid structures and reticulatedshells, so a kind of new-style buckling restrained brace is introduced, both the coresteel member and outer steel member are adopted. The new-style buckling restrainedbrace may be applied for the monitoring and controlling the stability of some keycomponents in the space grid structure. The lateral deformation of inner tube is usedto monitor and the outer tube is used to control the increasing deformation of innertube in which instability occurs.Firstly, the dissertation has tried to develop the structural instability theories,which can make the new-style buckling restrained brace carry through the function ofmonitoring and controlling.Secondly, for the determination of the interspaceδthat is from the inner tubesurface to the outer tube surface, the dissertation selects an example of utilizing ahalf-wave deformation to monitor this kind of braces. Making use of the theories thatincludes edge fiber yield criterion and stability safety spare coefficient of steelstructure, the calculated equation of the appropriate interspaceδis thereforededuced. The influence of the interspaceδon monitoring and controlling ofinstability is further analyzed.Then, all the possible types of failure for new-style buckling restrained brace areanalyzed. The dissertation selects an example of utilizing a half-wave deformation tomonitor of this kind of brace. Considering that this kind of braces is to monitor andcontrol, the last failure type is determined, and the stiffness requirements includingthe inner tube and outer tube is analyzed.Finally, by considering the appropriate interspaceδand the stiffness of theinner tube and outer tube, a simplified mechanical model is imported into the ultimate bearing capacity analysis for new-style buckling restrained brace. The ultimatebearing capacity of different slenderness ratio in the braces is derived respectivelyfrom making use of finite element analysis, and the column curve of the brace isobtained through curve fitting. All of the analysis provides the basic theory andreference for practical work that makes the new-style buckling restrained braceapplied to actual structures.