超薄壁冷弯型钢C型墙架柱-楼层梁连接抗震性能试验研究

Experimental study on seismic performance of connection between cold-formed C section steel wall frame and floor beam

低层冷弯薄壁型钢房屋技术规程推荐的墙-梁连接施工工艺简单,但传力复杂,为探讨连接抗震性能,设计包括规程推荐及角钢加强的新型连接的4组8个C型截面墙架柱-楼层梁连接试件,对其进行低周往复加载试验,结果表明:试件耗能能力均较强,发生延性破坏,荷载作用下累积损伤均较大;柱腹板高度对规程推荐连接承载力影响较大,而对新型连接影响较小,极限状态时轴压比对新型连接承载力影响更明显;规程推荐试件延性系数均大于新型连接,在自攻螺钉脱落前变形能力较强;而新型连接变形能力相对较弱,轴压比为0.2时试件有较明显的屈服平台;为加强楼层梁及边梁腹板,防止过早发生局部屈曲,建议设计时对梁端部进行构造加强。

The construction detailing of wall frame-floor beam connection recommended by the technical specification for low-rise cold-formed thin-walled steel buildings is simple,but load transmission is rather complex. In order to study the mechanics of force transmission and seismic performance of the connection,8 full scale specimens,divided into 4groups,were tested under low-cycle loading. The results show that：（ 1） The energy dissipation capacity of the connections constructed by the specification and the new connections enhanced by angles are strong,the damage and failure modes are ductile,and the accumulated damage index are large.（ 2） The height of the web has a certain influence on the bearing capacity of the connection recommended by the specification,but has little influence on the bearing capacity of the enhanced connection.（ 3） The ductility factor of recommended connections are larger than that of the new connections,before the self-tapping screws off,regional deformation of the connection is large. The ductility of the enhanced connection is mainly provided by the floor beam bend,the deformation capacity is relatively weak,specimens under an axial compression ratio of 0. 2 have obvious yield platform.（ 4） The connections are suggested to be simplified as nominally pinned when calculating the structure,and the ends of the beam should be enhanced to avoid premature local buckling of the beam web.