Experimental study on The Distortional Bucking of Ultimate Thin-Walled Open Section Member

首先介绍了为阐明超薄壁受压构件局部破坏和变形屈曲的基本性能而进行的约1.0 mm厚的薄壁唇形槽钢短柱的受压试验结果，然后详细阐述了基于屈服线理论的数值分析方法。研究结果如下：1)板的局部屈曲强度不仅与宽厚比有关，而且与相邻板的性能有关。特别是凸缘长度对凸缘强度有很大影响。2)试验中观察到的变形屈曲破坏行为可以通过基于屈服线理论的分析得到很好的解释，在该模型中，唇缘被视为法兰的一部分，并且试验的最大强度也很好地满足Es…其次，给出了双唇槽梁的负弯曲试验结果，以及可能的刚度和强度评估方法，并讨论了刚度、强度和破坏模式，将试验结果和分析结果进行了比较。研究结果表明：1)试件存在局部屈曲、翼缘变形屈曲和腹板变形屈曲三种形式，它们的变形增长相互影响，但侧向支承间隔较短的试件以翼缘变形屈曲为主，侧向支承间隔较大的试件以腹板变形为主。Ii)随着唇形槽道高度的增加和侧向支承间隔的增大，变形屈曲强度趋于减小。3)考虑变形屈曲影响的有限条法分析得到的屈曲强度与试验结果吻合较好。较少

A report has been presented to report findings obtained from the research supported by the Grant-in-Aid.The report first introduces the results of compression tests of light-gauge lipped channel short columns with plate thickness equal to about 1.0 mm that has been carried out to clarify the fundamental behavior of ultra thin-walled compression members failing in the local and distortional buckling, and then the method of numerical analysis based on the yield line theory is thoroughly explained. The research findings are as follows : i) Local buckling strength of a plate is affected by not only width-thickness ratio but also the behavior of adjacent plates. Especially, flange strength is strongly affected by lip length. ii) Failure behavior due to distortional buckling observed in the tests is well explained by the analysis based on the yield line theory using a mathematical model in which the lip is treated as a part of the flange, and the experimental maximum strength is also well es … More timated by the yield line analysis.Secondly, the report shows the results of negative bending tests of beams consisting of two lipped-channels, and the possible stiffness and strength evaluation methods, and then discusses stiffness, strength, and failure mode, comparing the results of tests and analysis. The research findings are as follows : i) Three kinds of buckling, local buckling, flange distortional buckling and web distortional buckling, occur in a specimen, and their deformations grows affecting each other, but the deformation of flange distortional buckling becomes predominant in the specimens with shorter lateral support interval, while that of web becomes predominant in the specimens with longer lateral support interval. ii) Distortional buckling strength tends to become smaller, as the height of the lipped channel becomes taller, and the lateral support interval becomes longer. iii) The buckling strength obtained by the analysis considering the effect of distortional buckling based on the finite strip method agrees well the experimental results. Less