Experimental And Theoretical Study On Axial Compression Performance Of Cold-formed Steel Composite Wall Filled With Vitrified Microbead-Gypsum Based Material

The traditional cold-formed steel composite wall is assembled from cold-formed steel skeletons and double-sided gypsum boards through self-tapping screws.In order to enhance the stiffness and the bearing capacity of the wall and improve the performance of the wall heat preservation and thermal insulation,this paper infills vitrified microbead-gypsum based lightweight material on the basis of the traditional combination wall,and explores a new type of cold-formed steel composite wall with excellent performance.This paper respectively conducted on the full-scale axial compression experiment researchs about one cold-formed steel cavity composite wall with double-sided gypsum board and two cold-formed steel composite walls with filled vitrified microbead-gypsum based materials,observed the wall test process and summarized the failure characteristics,and then conducted in-depth comparative analysis of the keel strain,axial compression bearing capacity and failure modes of test sample,the study found that: the cold-formed steel cavity wall occurs buckling failure,and the cold-formed steel composite wall with filled vitrified microbead-gypsum based materials eventually occurs intensity destruction;compared with the unfilled wall,the new type of filled composite wall has a significant increase in bearing capacity and stiffness.Based on the experimental study,the ABAQUS finite element software was used to conduct the Numerical Simulation about the cold-formed steel composite wall filled with vitrified microbead-gypsum based materials,and the failure characteristics,load-displacement curves and ultimate bearing capacity were compared with the test results to verify the correctness of the finite element modeling method.Then,the influence of five factors,including the strength of filling material,the wall thickness of the column,the number of columns,the height of the column and the bond-slip coefficient on the ultimate bearing capacity and stiffness of the composite wall were analyzed.The results showed that:(1)The ultimate bearing capacity and stiffness of the specimens are increased with the improvement of the filler strength,and the higher the strength of the test samples,the greater the displacement corresponding to the ultimate bearing capacity.(2)With the increase of the wall thickNess of the column,the deformation of the end of the column increases,the stressdistribution becomes more uniform,and the ultimate bearing capacity and rigidity continue to increase.(3)Under the condition of constant height and width of the test wall,the more the number of columns,the greater the ultimate bearing capacity and stiffness.(4)Increasing the height of the column web can effectively increase the ultimate bearing capacity and stiffness of the combined wall,and the degree of damage is also weakened.(5)The change of the bond slip coefficient has only a slight effect on the bearing capacity and stiffness of the combined wall,which can be neglected.The axial forces and axial force-strain curves of all sections of the columns of all test samples were extracted to further illustrate that the force mechanism of the ultimate intensity destruction of the test samples under the condition that the column is uniformly compressed.,The design and calculation recommendations of the vertical bearing capacity of this type of cold-formed steel composite wall filled with vitrified microbead-gypsum based materials have been proposed.After the trial calculation,it was found that the correlation coefficient ηbetween 0.6 and 0.75 can reasonably be obtained the ultimate bearing capacity of cold-formed steel composite wall filled with vitrified microbead-gypsum based materials.