Study On The Properties Of The Single Column With The Light-gauge Steel-concrete Column Composite System

Light-gauge steel-concrete column composite system is a new structural systemwhich is composed of thin-walled steel tubes and concrete. It is necessary to do a seriesof basic research work on the mechanical properties for the column-the maincomponents of the system in order to get the performance of vertical bearing capacity,horizontal shear bearing capacity, lateral stiffness, deformation, failure mode and etc.In the part of study on performance under the axial pressure, experiments on theshout column with different sections were completed. Besides, experiments on twodifferent columns of the Light-gauge steel-concrete column composite system havedone to get the failure mode under low cyclic loading, hysteretic characteristics,skeleton curve and ductility. The hysteretic characteristics, skeleton curve and theseismic performance of the two columns were compared and analyzed. Thenon-linearity finite element software-Abaqus is carried out to compare with the resultsof the experiments and the experiments are simulated successfully by the models.According to the experimental study and the theoretical analysis, this article getsthe following conclusions:○1It is recommended that the sheet core column is not feasible to bear the verticalload all by itself for the great influence of great dispersion, loading speed, concretevibrating compaction degree, specimen fabrication errors, initial eccentricity.②The square steel tubes and the concrete did not work as a whole although theywere connected by the butterfly-like clips. Single square steel tube and concrete formedthe ideal steel pipe concrete stress pattern if the tubes were poured into the concrete.The stress mode can significantly improve overall ultimate bearing capacity and theoverall performance can be improved. Concrete and tubes could bear the force and bedeformed together if the concrete were compact and there were no gap between them.The performance of the tubes could not play fully under axial compressive load if thetubes were not poured into concrete. And the concrete take most of the pressure.③According to the hysteretic experimental study, the initial stiffness of theFXZ-1100is larger than that of the FZ-1100for the action of the concrete. Thehorizontal bearing capacity of the FXZ-1100is approximately3.5times than that ofFZ-1100and the ductility coefficient is2times than the latter, which proves that it isgood to improve the seismic performance of the structure if the square columns are combined with concrete.④It can effectively improve the force of the column for the constraint function bythe butterfly-like clips. So it is advised that the first clips should be arranged near theend of the column of as far as possible in the engineer.⑤The theoretical analysis confirmed that the model one, which connected the clipsand the square steel tubes by the points and the surfaces, is close to the experimentalresults for the square core column. While the model three which takes the damagedconcrete model simulates the relationship between the load and the displacement well.