Experimental Research On The Axial Compression Capacity Of Cold-Formed Thin-Walled C-Shaped Steel PEC Column

Chinese construction industry has developed rapidly in recent years,and some emerging composite components with good performance have been gradually used in structural design and construction.PEC structure is a new combination form of steel and concrete.It combines steel and concrete together,exerting the respective advantages of the two materials.Its overall strength is significantly better than traditional reinforced concrete structures and steel structures.The cold-formed thin-walled C-shaped steel has high development and utilization value because it’s light and thin,easy to process,high strength and good ductility.The cold-formed thin-walled C-steel PEC column studied in this paper is a new type of cross-section PEC column,and its force and deformation characteristics are studied and summarized through experimental analysis and simulation analysis.In order to study the mechanical performance of cold-formed thin-walled C-shaped steel PEC composite columns,two cold-formed thin-walled C-shaped steel back-to-backs are used to form an I-shaped section by backing plates and high-strength bolts,and then transverse tie rods are welded between the flanges on both sides to form steel Skeleton,and then pour concrete inside to make 9 cold-formed thin-walled C-shaped steel PEC columns,and carry out axial compression bearing capacity tests on them The test mainly considered factors such as the thickness of the backing plate,the spacing of the backing plate,and the type of C-shaped steel.The factors are analyzed influencing the bearing capacity of cold-formed thin-walled C-section steel PEC composite columns,the load-strain curves of the web and flange are researched.The results show that the main factor influencing the bearing capacity of cold-formed thin-walled C-shaped steel PEC short columns is the type of C-shaped steel,that is,the size of the column section.The larger the C-shaped steel model,the higher the bearing capacity of the PEC column.The spacing of the pads,the thickness of the pads and the length of the anchor bolts have little effect on the ultimate bearing capacity of the PEC column.Before the experiment ultimate bearing capacity occurs,it can be analyzed that C-shaped steel and concrete have a good ability to worktogether.According to the superposition principle,a formula for calculating the ultimate bearing capacity of PEC column is proposed.The theoretical calculation meets the error requirements compared with the actual experiment.The bearing capacity calculated by the formula is basically lower than the ultimate bearing capacity of the test,which is safer.Based on the test results,the large-scale finite element analysis software ABAQUS was used to establish a test model and expand analysis.The failure mode of the simulated specimen and the corresponding curve obtained are similar to those of the test,and the simulation results are basically consistent with the test results.From the simulation results,it can be concluded that increasing the strength of steel and the strength level of filled concrete can increase the bearing capacity of PEC columns.