Experimental Study On Mechanical Behavior Of Aluminum Foam-polyurethane Filled Steel Tube Composite Columns

The purpose of this paper is to explore the possibility of applying Aluminum Foam materials to the field of structural vibration control.Aluminum Foam and Aluminum Foam /Polyurethane composites were used as the basic research objects in this paper.Experimental studies focusing on the Aluminum Foam and Aluminum Foam /Polyurethane composites material and the steel composite column were conducted,respectively.The main research works and related conclusions are as follows:Monotonous compression and tensile-compression cycle tests at the material level and seismic performance test for steel composite column at component-level were carried out.The main research works and related conclusions are as follows:1.The monotonic compression mechanical behavior of three spherical porous Aluminum Foam and their composites(24 specimens)with the height-diameter ratio of 1,pore sizes 5~6mm,7~8mm,and 9~10 mm have been investigated.The mechanical behavior of the spherical open-cell Aluminum Foam and its composites during compression are discussed.The stress-strain curve of each specimen were compared and analyzed.The test results demonstrated that the mechanical behavior of spherical porous Aluminum Foam and Aluminum Foam/Polyurethane composites exhibit a significant three-stage mechanical characteristic under monotonic compression,i.e.elastic stage,plastic platform stage and compaction stage.The mechanical behavior of aluminum foam and its composites with 7~8mm pore size showed the least dispersion.The addition of polyurethane material effectivelly delayed the crash of the Aluminum Foam.In the plastic platform stage,polyurethane greatly enhance the strength,stiffness and deformation ability of Aluminum Foam.2.The tension-compression mechanical behavior of three spherical porous Aluminum Foam and their composites(18 specimens)with pore size 7~8m,and height-diameter ratios of 1,1.5 and 2 were investigated.The backbone curves and hysteretic energy dissipation characteristics of each specimen under tension-compression cycles were compared and analyzed.The results demonstrated that in the strain range of engineering application,the bearing capacity and energy dissipation capacity of pure Aluminum Foam can be enhanced by the addition of polyurethane,and the bearing capacity and energy dissipation capacity of Aluminum Foam can also be increased with the increase of the ratio of height to diameter.3.The seismic performance of hollow steel tube column,Aluminum Foam filled steel tube composite column and Aluminum Foam-Polyurethane filled steel tube composite column(3 components)were studied experimentally.The strength,deformation and energy dissipation capacity of test columns were compared and analyzed.The results demonstrated that: The polyurethane can delay local buckling of the steel tube.Compared with hollow steel tube column,the strength,stiffness,ductility and energy dissipation capacity of Aluminum Foam filled steel tube composite column and Aluminum Foam-Polyurethane filled steel tube composite column members under low cycle reciprocating load are improved.Filling spherical porous Aluminum Foam and Aluminum Foam/Polyurethane composites could improve the seismic performance of hollow steel columns to some extent.