Cold-formed lipped channel sections have been widely used in light gauge steel construction. Among the several possible buckling modes, the distortional buckling mode involving rotational deformation of the flange–lip combination about the flange–web junction is often the strength-governing mode. While many studies have been carried out on this buckling mode, the method of Lau and Hancock (J. Struct. Eng. ASCE 113 (1987) 1063), which models the phenomenon as the flexural–torsional buckling of the flange–lip combination with elastic restraints from the web appears to be the most effective in producing a relatively simple closedform solution for design use. This article extends the Lau and Hancock method, which was developed for axially loaded columns to beam-columns subjected to combined axial compression and biaxial bending. Particular attention is paid to the case of axial compression in combination with uniaxial bending in the plane of symmetry. Numerical results from the present closed-form solution are compared with those from the finite strip method, showing a close agreement between the two. The numerical results also lead to a number of useful observations on the distortional buckling behavior of these beam-columns, which should be useful in the future development of a simplified solution for direct design use.

Large elevated steel silos generally consist of a cylindrical vessel, a conical discharge hopper and a skirt which may either be supported on the ground or by a number of columns. The cone-cylinder-skirt junction is subject to a large circumferential compressive force due to the radial component of the meridional tension in the hopper, so either a ring is provided or the shell walls are locally thickened to strengthen the junction. Many theoretical studies have examined the buckling and collapse strengths of these junctions, but no previous experimental study has been reported. This has been due to the great difficulties associated with testing these thin-shell junctions at model scale. This paper first describes the development of an experimental facility for testing model steel silo transition junctions. Issues covered include the fabrication of quality model junctions using thin steel sheets, the loading method and the precise three-dimensional measurement of geometric imperfections and deformed shapes using a laser-displacement meter. Typical experimental results of a cone-cylinder-skirt-ring junction are next presented to demonstrate the capability of the developed facility. Procedures for processing the test results to determine both the buckling load and the number of buckling waves are also presented.

简仓结构广泛应用于农业、矿业、化工、电力等诸多领域中的散料储存。混凝上筒仓在国内已有许多应用，但钢筒仓的应用还很有限。过去二十年里国际上对钢简仓结构的性能致强度进行了大量的研究，香港理工大学在近几年也进行了许多研究。本文总结了大型圆形钢筒仓结构行为及设计方面的近期研究进展。首先对钢筒仓的结构形式及散料荷载进行简单讨论，并介绍钢筒仓的主要破坏形式发相应的研究，给出了可供钢筒仓结构设计直接应用的部分主要设计公式。还介绍了钢筒仓结构设计中的计算机分析方法，最后指出钢筒仓结构尚需进一步研究的课题。

轴压圆柱薄壳广泛应用于土木工程中的各类钢壳结构，包括筒仓、塔桅、烟囱及容器等。轴压圆柱壳的屈曲问题一直是壳体稳定研究中最为活跃的课题之一。本文全面总结轴压圆柱壳稳定设计方面的研究成果及设计准则。首先简要回顾轴压圆柱壳的弹性经典解及初始缺陷敏感性的经典研究，接着对实际结构中的初始缺陷与制作过程的关系以及焊接残余应力对屈曲强度影响的近期研究进展进行了总结。然后：在简单介绍欧洲钢结构协会规程对轴压圆柱壳稳定设计有关规定的基础上，详细说明了新的欧洲钢壳设计规范所给出的设计准则及相应的研究背景。

In this paper, the most up-to-date research on the buckling of internally-pressurized cone±cylinder intersections and state-of-the-art ®nite element analyses are deployed to provide another anatomy of a pressure vessel failure due to mis-operation overpressure recently reported and analyzed by Jones [Jones, DRH. Buckling failures of pressurized vessels: two case studies. Engineering Failure Analysis 1994;1:155±67]. Existing research on these intersections is ®rst outlined, followed by a description of the buckling strength formulae recently developed to approximate ®nite element buckling loads of the perfect geometry. The validity of these formulae for real vessels with geometric imperfections is next examined through a comparison of theoretical predictions with experimental results, which establishes the limited sensitivity of the buckling load to initial imperfections. The buckling pressure of the cone±cylinder intersection in the failed vessel is then determined using these formulae, while the buckling pressure of the spherical partition in the vessel is evaluated using the ECCS rule. These calculations demonstrate that the cone±cylinder intersection buckled ®rst, followed by the buckling of the spherical partition, which also released the vessel from overpressure. The buckling pressure of the spherical partition is therefore also the maximum pressure exerted on the vessel. This proposition is con®rmed by postbuckling analyses of the vessel.