冷弯薄壁卷边槽钢檩条弯曲变形的抗弯刚度

Bending rigidity of cold-formed thin-wall lipped channel purlins for bending deflection

在分析比较欧洲规范EN 1993-1-3和我国《冷弯薄壁型钢结构技术规范》（GB 50018—2002）的基础上,针对冷弯薄壁卷边槽钢檩条弯曲变形的抗弯刚度进行了较深入的探讨和对比分析。计算结果表明：按《冷弯薄壁型钢结构技术规范》（GB 50018—2002）计算有效截面抗弯刚度相对保守,按毛截面计算抗弯刚度稍显不安全,按EN 1993-1-3计算相对合理。在满应力状况下,对于2mm厚C140~C250规格的冷弯薄壁卷边槽钢檩条,在正常使用极限状态下,抗弯刚度折减系数可取毛截面抗弯刚度的0.95倍（Q235钢）和0.9倍（Q345钢）。

Based on the comparison analysis of Eurocode EN 1993-1-3 and Technical code of cold-formed thin-wall steel structure（ GB 50018—2002） in China,intensive study and comparison analysis were carried out about the bending rigidity of cold-formed thin-wall lipped channel purlins for bending deflection. The calculating results show that the provisions in the GB 50018—2002 specifications are too conservative about the effective section bending rigidity and the bending rigidity calculated according to gross cross-section is unsafe,while the results are reasonable according to the EN 1993-1-3. Under the full stress condition,the reduction factor for the bending rigidity of cold-formed thin-wall lipped channel purlins from C140 to C250（ thickness of 2mm） are 0. 95 times（ Q235 steel） and 0. 9 times（ Q345 steel） of the gross cross-section bending rigidity respectively at the serviceability limit state.