Analysis On Seismic Behavior Of Light-steel Frame Structure With Different Forms Of Concentrically Brace

As a kind of environmental friendly building materials with high degree of industrialization,light steel has been developing rapidly in the steel structure system recent years.Because of light steel structural member have some characteristics such as light weight and strong deformation ability,the light steel structural may have a greater lateral shift and lead to whole structural damage under seismic effect,which threaten the safety of people's life and property.The concentrically braced light-steel frame as one of the light steel structure residential system,it's support part and frame part form a double resists horizontal force system,can provide a better resistance of lateral force and also have a simple construction principles,the economic returns in the resistance to horizontal seismic action and wind load is higher,so it occupies an important position in the multi-storey and the middle light steel structure residential system.In this paper,on the basis of previous studies,using the finite element software ANSYS15.0,designed and built four kinds of different forms of braced frame model based on a project.By using the modal analysis and time-history response analysis method,this paper study the performance of lateral resistance and dynamic characteristics,focused on the research of the model's changes situation under two strong records and a manual-simulation frequent and rare seismic effect,in several information such as Top-floor displacement?Displacement(Angel)between the floors?Each column's maximum axial force and moment?Each brace's maximum axial force?Bottom maximum shear,and study the influence to the light-steel frame with different kinds of concentrically brace.The result shows that:(1)By adding the concentrically brace,the lateral stiffness of light-steel frame has obviously improved,among them,the chevron-braced light-steel frame have the biggest lateral stiffness,with a less level of steel amount.(2)By adding the concentrically brace,can effectively reduce the displacement of top floor,and the displacement(angel)between the floors,the cross-braced and chevron-braced and V-shaped braced light-steel frame have a better performance.(3)After adding the concentrically brace,the maximum axial force of each floor's column is increases,the maximum bending moment is generally decreases in low-floors and increases in high-floors,the chevron-braced light-steel frame have a less axial force of columns with minimum bending moment.(4)The cross brace have less axial force under seismic effect;the total shear at the bottom of the frame is increased to a certain extent after adding the concentrically brace,this increase is generally small in the V-shaped braced light-steel frame.(5)In the four kinds of concentrically braced light-steel frame,the chevron-braced light-steel frame has a better performance in displacement and internal force under seismic effect.