Analysis Of Mechanical Properties Of Light-duty Steel Composite Section And Welded Composite Section Column

As national sustainable strategy further moves forward,the emphasis of construction works is gradually developing from quantity to high quality,and the promotion and application of green building has been followed with strong interest in the engineering field.Considering the fact that light steel structure is featured with less pollution,recycling,light weight and good seismic performance and it has been developed rapidly in low-rise buildings in China.As the main load-bearing member in light steel structure system,it is very important to study the mechanical properties of the built-up section column.It is the light steel built-up column with thickness of about 1 mm that is often used by the cooperative enterprise in this project.There are corresponding design requirements for the composite section of 2-6 mm thickness in the Chinese Standard,whereas there are no clear provisions for the design and application of thin-walled members.Therefore,this paper studies the composite section column with a thickness of 1 mm.The main research contents include: PKPM was used to analyze the internal forces of the actual project using light steel keel system to add layers,and two kinds of built-up section columns are determined as the research object.Moreover,two kinds of column with built-up section are analyzed theoretically,and the square steel section with the same moment of inertia is compared.Next,the bearing capacity and mechanical properties of 18 specimens in 6 groups were analyzed.Finally,the finite element software is used to simulate the corresponding test specimen,and the bearing capacity of theoretical calculation,experimental study and finite element simulation is compared and analyzed,which provides a reference for engineering application in enterprises.The main conclusions of this paper are as shown below:(1)The test results show that the bearing capacity of the assembled members is greater than that of the simple superposition of the single-supported members,which improves the bearing capacity of the members;(2)Two theoretical methods are used to calculate the bearing capacity of axial compression,as well as experimental study and finite element simulation analysis.It can be seen that the single-limb superposition correction theory of the "Technical Specification for Low-rise Cold-Formed Steel Building Construction" is more reasonable for built-up box section members;It is more reasonable to adopt the effective width theory of the "Technical Specification for Cold-Formed Thin-walled Steel Structures" for open built-up section members;(3)Through the comparative study of square steel with the same moment of inertia and built-up section members,the bearing capacity of the corresponding square steel ishigher than that of the built-up box section column after the section area conversion,and the axial compression performance is more stable.However,the bearing capacity of open built-up section column is better than that of square steel;(4)After conducting structural design,theoretical calculation,experimental study,finite element simulation and other studies,it is verified that the bearing capacity of light steel built-up section column meets the requirements and has certain safety reserve,which provides a reference for the engineering application of enterprises.