Analytical effective width equations for limit state design of thin plates under non-homogeneous in-plane loading
Analytical effective width equations for limit state design of thin plates under non-homogeneous in-plane loading
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DOI：
10.1007/s00419-009-0296-z
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发表时间：
2009-02
影响因子：
2.8
通讯作者：
O. Bedair
中科院分区：
文献类型：
--
作者：
O. Bedair
有效宽度概念已广泛应用于细长构件极限强度的计算中。许多设计规范采用这一概念，以补偿后屈曲状态下的刚度降低。对于均匀压缩条件下板的有效宽度方程的研究已经做了大量的工作，而对于非均匀面内加载条件下板的有效宽度方程的研究却很少。北美、英国和欧洲的设计规范仅规定了这种荷载组合下板的弹性屈曲载荷计算表达式，而有效宽度的计算是基于均匀受压板的。结果表明，由于外加载荷的非均匀性，后屈曲状态下的应力特征与均匀压缩情况不同，因此需要特殊处理。本文给出了计算非均质面内荷载作用下薄板有效宽度的解析封闭表达式。假定纵向边缘是直的，可以在板的平面上自由移动。所提出的表达式对于这种一般荷载下细长工字截面梁柱或槽形截面的极限状态设计具有重要的指导意义。它们使设计人员能够借助简单的公式来计算截面的有效宽度，这些公式对于设计目的来说适合手工计算，并且避免了任何数值非线性分析可能需要的成本和精力。
The effective width concept has been widely used in engineering practice for the computation of ultimate strength of slender members. Many design codes employ this concept in order to compensate for the stiffness reduction in the post-buckling state. Extensive work was done to develop effective width equations for plates under uniform compression, while little attention has been given for plates under non-homogeneous in-plane loading. North American, British and European design codes provide only expressions for the computation of the elastic buckling loads for plates under this load combination, while the effective width calculation is based on the uniformly compressed plates. It will be shown that due to the non-uniformity of the applied load, the stress characteristics in the post-buckling state are different from the uniform compression case, thus requiring special treatments. The paper presents analytical closed form expressions for the computation of effective width of thin plates under non-homogeneous in-plane loading. The longitudinal edges are assumed to be straight and free to translate in the plane of the plate. The proposed expressions are very useful for limit state design of slender I-sections of beam columns or channel sections under this general type of loading. They enable the designers to compute the effective width of the section with the aid of simple formulas that, for design purposes, are suitable for hand-calculation and avoid the cost and effort that any numerical non-linear analysis may require.