Mechanics Property Analysis And Research On Bearing Capacity Of Square Steel Tube Columns Filled With Steel-reinforced Concrete Subjected To Eccentric Loading

With the development of the multi-floor and high-floor building, thesteel-concrete composite structure is paid more and more attention bypeople. As a new steel-concrete composite structure, the use of square steeltube columns filled with steel-reinforced concrete will increase widely inthe engineering. At present, more studies are focused on square steel tubecolumns filled with steel-reinforced concrete subjected to axis force, butsquare steel tube columns filled with steel-reinforced concrete undereccentric loading are relatively ignored. The nonlinear simulation andtheoretical analysis were conducted to investigate the mechanical behaviorsof square steel tube columns filled with steel-reinforced concrete undereccentric loading. The content and related conclusions have the followingsides:(1) The numerical simulation analyses was conducted to investigate themechanical behaviors of square steel tube columns filled withsteel-reinforced concrete under eccentric loading by ANSYS software. Onthe basis of testing this model, the failure mode of square steel tubecolumns filled with steel-reinforced concrete was analyzed. The tests showthat the square steel tube in compression zone and steel-reinforced reach theyield point when load attain ultimate bearing capacity, but the square steeltube in tension zone does not reach the yield point. Furthermore,mechanical behavior was studied corresponding to different parameterssuch as concrete strength grade, slenderness ratios, eccentric distance,thickness of steel pipe, index of steel reinforced. The results show ultimatebearing capacity increase with the increase of concrete strength grade. Theincrement of the slenderness ratios leads to the decrement of ultimatebearing capacity. The increment of eccentric distance leads to the decrementof the bearing capacity. The increment of thickness of steel pipe leads to theincrement of ultimate bearing capacity. The increment of index of steelreinforced slowly leads to the increment of ultimate bearing capacity.(2) Combining the solution of ANSYS, the influence of slendernessratios, concrete strength grade, thickness of steel pipe, eccentric distanceon ultimate bearing capacity of square steel tube columns filled with steel-reinforced concrete under eccentric loading has been studied usingorthogonal experiments, and the influence of each factor and level onindexes is discussed.(3) The ultimate state design method and superposition method wasused to calculate ultimate bearing capacity of square steel tube columnsfilled with steel-reinforced concrete under eccentric loading. Compared theresults with the experiment date and the solution of finite element, theresults show that the ultimate state design method and superposition methodcan forecast ultimate bearing capacity of square steel tube columns filledwith steel-reinforced concrete under eccentric loading, and this is tend tosafety. Finally, reliable bases for engineering design are presented.