Study On Mechanical Properties Of New Type High Strength By Bending Of Thin-walled Cold-formed Steel Members

With the rapid development of science and technology, steel structure with its superior performance and flexibility in the world development speed is very fast. Because of the factors of production and protection of forest resources, steel frame become a traditional wood and masonry structure alternatives, steel structure building many a symbol of national scientific and technological strength and economic level. Steel structures in buildings compared to other material has many advantages:high strength, light weight, material uniformity, good plastic and toughness, excellent seismic performance, simple manufacture, high degree of industrialization, short construction period etc. With the rapid development of new light steel structure system application, cold-formed steel as load-bearing components, accessories, maintenance structure widely applied. Cold-formed thin-walled steel residence has been used widely, American, Japan, Australia, construction technology and production equipment and technology is already very perfect. Cold-formed steel in China began in twentieth Century fifty years in1987, official publication of the national standard "code for design of cold-formed thin-walled steel structures"(GBJ18-87), the current specification standard "Chinese cold-formed thin-walled steel structure"(GB50018-2002).First of all by the mechanical properties of curved case for the study of new high strength cold-formed thin-walled steel members, the subject of Liang Jin hang test before and after bending, finite strip model, finite element simulation and China standard rough estimate. The new high-strength cold-formed members calculated by4different forms of research, analysis of bending members get accurate mechanical property data.And then the resulting data collation and analysis, research shows that:the bending test and finite element analysis of component failure mode in the local buckling control; pure bending is distortional buckling control role in destroying process component lines and finite element analysis. Finally, the obtained data and comparative analysis were performed to compare, research shows that: the ratio of height to thickness and width to thickness ratio is too large or too small are prone to instability, when the aspect ratio is between2-4, component has good load capacity; direct strength method and experimental calculation of limit bending moment ratio between1.95-2.97the critical moment, in comparison with experimental values of ANSYS analysis between1.8-2.44,the calculation analysis results with the experimental data curve curve has the same structure with ANSYS direct strength method, and has certain safety margin, more practical engineering use, should be strongly in China’s large-scale promotion and application.