加斜撑冷弯薄壁型钢组合墙体的抗震性能

Seismic performance of diagonally braced cold-formed thin-walled steel composite walls

通过对竖向荷载作用下加斜撑冷弯薄壁型钢组合墙体的抗震性能试验研究,考察了墙体的受力特性、破坏模式和滞回性能,分析了覆面板对组合墙体滞回性能、延性和耗能能力的影响。结果表明:相同竖向荷载作用下,单面覆OSB板墙体较无面板墙体的抗剪承载力提高了38.79%;墙架柱轴压比为0.24较轴压比为0.16的单面覆OSB板组合墙体抗剪承载力提高了7.5%,屈服位移降低了8.1%,墙体延性系数μ提高了4.5%,耗能系数E提高了4.1%,加斜撑冷弯薄壁型钢组合墙体体现出较好的抗震性能。在对有限元模型可靠性进行验证的基础上,通过变参数分析考察了墙架柱轴压比、钢龙骨屈服强度对墙体受力性能的影响规律,结果表明:随墙架柱轴压比的增大,组合墙体的抗剪承载力有所提高;减小钢龙骨的屈服强度,组合墙体的抗剪承载力下降明显。依据《低层冷弯薄壁型钢房屋技术规程》(JGJ 227—2011)和美国规范AISI S400-15,推导出墙体的抗力分项系数,确定了水平地震作用下此类墙体的抗剪承载力设计值。

Through an experimental investigation of the seismic performance of diagonally braced cold-formed thinwalled steel composite walls subjected to vertical loads,the mechanical properties,failure modes,and hysteresis properties of the walls were elucidated.In addition,the influence of a sheathing panel on the hysteresis performance,ductility,and energy dissipation of the composite walls was analyzed.The experimental results show that the shear bearing capacity of the single-sided oriented strand board(OSB)panel wall was increased by 38.79%compared with the non-panel wall under the same vertical load.The shear bearing capacity,ductility coefficient,μ,and energy dissipation factor,E,of the single-sided OSB panel composite wall with an axial compression ratio of 0.24 were increased by 7.5%,4.5%,and 4.1%,respectively,compared to the wall with an axial compression ratio of 0.16;however,the yield displacement was reduced by 8.1%.The cold-formed thin-walled steel composite wall with diagonal bracing exhibited good seismic performance.After verifying the reliability of the finite element model,the influence of the axial compression ratio of the wall stud and the yield strength of the steel components on the mechanical performance of the wall was investigated through a variable parameter analysis.The results showed that with the increasing axial compression ratio,the shear bearing capacity of the wall was improved.In addition,reducing the yield strength of the steel components significantly reduced the shear capacity of the composite wall.Finally,according to the Technical Specification for Low-rise Cold-formed Thin-walled Steel Buildings(JGJ 227-2011)and AISI S400-15,the resistance partial coefficient of the wall was derived,which determines the design value for the shear bearing capacity under a horizontal earthquake.