On the mechanics of local-distortional interaction in thin-walled lipped channel beams
On the mechanics of local-distortional interaction in thin-walled lipped channel beams
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DOI：
10.1016/j.tws.2017.05.035
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发表时间：
2018-07-01
影响因子：
6.4
通讯作者：
Dinis, Pedro Borges
中科院分区：
文献类型：
--
作者：
Martins, Andre Dias;Camotim, Dinar;Dinis, Pedro Borges
本文研究了受局部畸变（L-D）相互作用的简支卷边槽形薄壁梁的弹性后屈曲行为。梁绕主轴均匀弯曲，并经历凸缘触发的局部屈曲（实践中最常见的情况）。考虑了三种光束几何形状，每种都表现出不同类型的L-D相互作用，即（i）“真实L-D相互作用”（接近的局部和畸变临界屈曲力矩-使用两种临界模式初始几何缺陷，类似于竞争临界屈曲模式），（ii）“二次局部分叉L-D相互作用”或（iii）“二次畸变分叉L-D相互作用”（临界畸变与局部屈曲力矩之比分别远低于或高于1.0，屈服应力“足够高”）。所提出和讨论的结果是通过弹性几何非线性广义梁理论（GBT）分析获得的，并提供了演化，沿着给定的平衡路径，梁变形配置（表示在GBT模态形式），相关的位移剖面和模态参与图，使人们有可能获得深入的知识梁L-D相互作用力学。特别注意致力于解释与上述三种L-D相互作用类型相关的梁后屈曲行为所表现出的定量和定性差异。
This paper investigates the elastic post-buckling behaviour of simply supported thin-walled lipped channel beams undergoing local-distortional (L-D) interaction. The beams are uniformly bent about the major-axis and experience flange-triggered local buckling (most common situation in practice). Three beam geometries are considered, each exhibiting a different type of L-D interaction, namely (i) "true L-D interaction" (close local and distortional critical buckling moments-two critical-mode initial geometrical imperfections are used, akin to the competing critical buckling modes), (ii) "secondary local-bifurcation L-D interaction" or (iii) "secondary distortional -bifurcation L-D interaction" (critical distortional-to-local buckling moment ratio well below or above 1.0, respectively, with "high enough" yield stresses). The results presented and discussed are obtained through elastic geometrically non-linear Generalised Beam Theory (GBT) analyses and provide the evolution, along given equilibrium paths, of the beam deformed configuration (expressed in GBT modal form), relevant displacement profiles and modal participation diagrams, making it possible to acquire in-depth knowledge on the beam L-D interaction mechanics. Particular attention is devoted to interpreting the quantitative and qualitative differences exhibited by the beam post-buckling behaviours associated with the three aforementioned L-D interaction types.