压型钢板开孔受压翼缘的局部屈曲分析及设计对策

Local buckling analysis and design strategy on perforated compression flange of profiled steel sheet

有效宽度法或直接强度法计算压型钢板承载力的关键之一是计算截面板件的局部屈曲应力,而针对压型钢板开孔受压翼缘,目前尚无成熟的对其局部屈曲应力的计算方法。基于折减厚度法和折减面积法,参照无孔受压翼缘局部屈曲应力的计算思路,通过引入折减系数Be,提出了压型钢板开孔受压翼缘局部屈曲应力的实用计算公式。通过数值模拟对受压翼缘单开孔、单排均匀开孔及多排均匀开孔的局部屈曲进行分析,并与公式计算结果进行对比,研究了实用计算公式在不同开孔情况下的适用性。结果表明,折减面积法简单易行,相比折减厚度法计算精度更高,且能考虑纵横向开孔间距不同的情况,满足实际工程设计需要,为《冷弯薄壁型钢结构技术规范》（GB50018—2002）的修订提供依据。

One of the keys to calculate the carrying capacity of profiled steel sheet by direct strength method or effective width method is to calculate the buckling stress of section plate. For perforated compression flange of profiled steel sheet,there is no proven method to calculate its local buckling stress. Based on thickness reduction method（ TRM） and area reduction method（ ARM）,and referring to the thinking of local buckling stress calculation for no-perforated compression flange,the practical calculation formula for local buckling stress on perforated compression flange of profiled steel sheets was proposed by introducing the reduction coefficient Be. The local buckling stress on perforated compression flange with uniform openings,including single,single-row and multiple rows were obtained through the numerical simulation. The numerical results were compared to the practical calculation formula results,and the applicability under different opening conditions was discussed. It indicates that ARM is simple and easy to operate,which is more accurate than TRM,and could consider the different distances between the vertical and horizontal openings. Therefore,ARM is more efficient to meet the needs of actual engineering design,and provides the basis for the revision of Technical code of cold-formed thinwall steel structures（ GB 50018—2002）.