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

已经提交了一份报告，报告由援助赠款支持的研究所得的结果。本文首先介绍了薄板厚度约为1.0 mm的轻型唇形槽型短柱的压缩试验结果，阐明了超薄壁受压构件局部屈曲破坏和扭曲屈曲破坏的基本行为，然后详细阐述了基于屈服线理论的数值分析方法。研究结果表明：1)板的局部屈曲强度不仅受宽厚比的影响，还受相邻板行为的影响。特别是，法兰强度受唇长度的影响很大。ii)基于屈服线理论的分析很好地解释了试验中观察到的由扭曲屈曲引起的破坏行为，该数学模型将唇部视为法兰的一部分，并且实验的最大强度也很好地预测了屈服线分析。其次，给出了双唇形通道梁的负弯曲试验结果，以及可能的刚度和强度评估方法，然后讨论了刚度、强度和破坏模式，并对试验结果和分析结果进行了比较。研究结果表明：1)试件同时发生局部屈曲、翼缘畸变屈曲和腹板畸变屈曲三种屈曲形式，其变形程度相互影响，但侧向支撑间隔较短的试件以翼缘畸变屈曲变形为主，侧向支撑间隔较长的试件以腹板畸变屈曲变形为主。ii)变形屈曲强度随唇形通道高度的增加和侧向支撑间隔的延长而减小。iii)基于有限条法的考虑畸变屈曲影响的屈曲强度分析与实验结果吻合较好。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