双肢拼合冷弯薄壁型钢箱形截面梁受弯性能研究  

Research on flexural capacity of cold-formed steel double limbs built-up box beams

作　　者：石宇[1] 周绪红[1,2] 高婷婷 管宇[1] 

机构地区：[1]长安大学建筑工程学院,陕西西安710061 [2]重庆大学土木工程学院,重庆400045

出　　处：《建筑结构学报》2015年第11期20-28,共9页Journal of Building Structures

基　　金：国家自然科学基金项目(51108033);中央高校基本科研业务费专项(013G3283001)

摘　　要：为研究由单根C形和U形冷弯薄壁型钢拼合而成的箱形截面梁的受弯性能,对5组共计15个试件进行了静载试验。考察了梁跨高比、翼缘宽厚比、截面高宽比,以及连接螺钉间距对双肢拼合箱形截面梁破坏模式和受弯承载力的影响,并采用ANSYS有限元软件对双肢拼合箱形截面梁进行数值模拟与影响因素分析。结果表明：试件的破坏模式为跨中受压翼缘和腹板发生局部屈曲,屈曲半波长均为连接螺钉的间距。改变翼缘宽厚比和截面高宽比对双肢拼合箱形截面梁的受弯承载力影响较大,而改变连接螺钉间距（150~600 mm范围内）和梁跨高比对其受弯承载力影响较小。在有限元参数分析的基础上,提出了用于计算双肢拼合冷弯薄壁型钢箱形截面梁受弯承载力的抗弯模量折减法和计算式,并由试验数据验证了该简化计算方法的适用性。In order to investigate the flexural capacity of cold-formed steel double limbs built-up box beams,which were composed by single C- and U-section joist,a total of 15 cold-formed specimens with 5 groups were tested. Spanheight ratio,width-thickness ratio of flange,height-width ratio and screws spacing were taken into account to study the failure modes and flexural capacity of double limbs built-up box beams. And the finite element software ANSYS was adopted to simulate the tests and perform the parametric analysis. The following conclusions can be obtained： the compressed flange and web fail due to local buckling at the mid-span of specimens. The half wave length of local buckling is the screw spacing. The width-thickness ratio of flange and height-width ratio have a great impact on the flexural capacity of specimens,however,the screws spacing which was 150-600 mm and span-height ratio have a small impact on the flexural capacity of specimens. Finally,the bending modulus reduction method was proposed to calculate the flexural capacity of double limbs built-up box beams based on the parametric analysis,and the flexural capacity of the specimens from this method agrees well with the experiment results. So the simplified method is valid and can be applied to practical engineering.

关 键 词：冷弯薄壁型钢 双肢拼合箱形梁 静载试验 数值分析 受弯承载力 

分 类 号：TU392.503[建筑科学—结构工程]