冷弯薄壁型钢梁弯曲变形计算公式折减系数研究

Research on reduction factor in the defor mation for mula of cold-for med steel beam

由冷弯薄壁型钢构件组成的檩条梁体系在低层住宅建筑中的应用越来越广泛,但由于施加荷载的大小、位置、类型,梁的跨度及抗弯刚度等因素的影响,使得檩条梁变形的确定比较复杂.对于确定梁的变形性能的研究,设计规范中相关的条文不够成熟.通过对13根Q235冷弯薄壁型钢卷边槽型截面简支梁试件的试验进行了变形性能分析结果表明,北美规范按最大弯矩控制截面计算有效截面刚度作变形分析偏保守;我国的冷弯薄壁型钢技术规范按毛截面计算(相当于作等截面、等刚度梁分析)偏不安全.通过对该实验的数据进行参数分析,提出一个变形计算公式中较合理的折减系数.

The purlin - beam system with cold - formed steel members are more commonly utilized in the construction of low - rise buildings. Because the effect of size, location, type of the inflition load, long - span and bending rigidty, it is difficult to predict the distortion capacity of purlin - beam. The distortion capacity of beam used in the study is not well understood and the related design rules are not available. The deformation capacity behavior of a total of thirteen Q235 cold - formed lipped channel simple beams under bending has been studied in this paper. The results indicated that： according to the north America specification, the deformation analysis under effective cross - section rigidity calculated by controling the greatest moment was con- servative. In China specification, the deformation calculated by gross section （equivalent to analysis equal a cross - section and stiffness beam） appeared unsafety. Therefore, with the parameters＇ analysis of experimen- tal data, a more reasonable reduction factor in the deformation formula is put forward.