冷弯薄壁C和Z型钢组合框架低层住宅的承载能力比较

Comparison of load-bearing capacity of low level residential buildings with cold-formed thin-walled C and Z steel composite frames

利用遗传算法和直接强度法(DSM)得到轴压下优化后的冷弯薄壁卷边C和Z型钢,取相同截面积时两者的最优尺寸相同.利用有线条(CUFSM)和DSM,验证了单根冷弯C和Z型钢的临界屈曲荷载和极限承载力基本对应相等.随后,基于有限元软件SAP2000对冷弯薄壁型钢单层住宅整体建模,将优化后尺寸相同的C和Z型钢应用于结构中,施加相同的荷载,发现两者整体结构的临界屈曲载荷不同,Z型钢房屋框架屈曲后承载能力更高;承载薄弱的风向角所对应的Z型钢房屋组合框架屋檐等薄弱区域所承受的轴力较C型钢房屋更小,因此认为在用钢量相同的前提下,低层房屋建设选择Z型截面更优.

By using genetic algorithm and Direct Strength Method (DSM), the optimized cold-formed thin-walled lipped C and Z steel sections after axial compression are obtained. The same optimal size is obtained when considering the same cross-sectional area. Using the linear (CUFSM) and DSM, the conclusion was verified that the critical buckling load and ultimate bearing capacity of single cold-formed C and Z steel are almost equal. Then, based on the finite element software SAP2000, the overall modeling of cold-formed thin-walled steel single-storey house is conducted. C and Z beams of the same optimized size are utilized in the structure, and the same loads are applied. It is found that the critical buckling loads of the two structures are different, and the bearing capacity of the Z-beam housing frame is higher after buckling. Under the wind direction with weak bearing capacity, the axial force in eaves and other weak areas of the combination frame of Z-shaped steel house is smaller than that of C-shaped steel house. Therefore, it is considered that under the premise of the same amount of steel used in low-rise housing construction, it is better to choose the Z-shaped section.