Ordinary (customary) light gauge steel framing is a convenient construction technology; however, given the studs low axial capacity, it has been considered mainly for low-rise buildings in low seismicity regions. This paper investigates the boundaries of application of this type of steel framing (in moderate and high seismicity areas) by designing the structures of three representative 5, 7 and 10-storey buildings in order to examine their feasibility. The necessity of using built-up columns consisting of two or more sections is investigated. The axial capacity of studs is estimated by code-type analyses. The critical buckling stress is determined with well-known closed-form expressions; as they do not contemplate the flexibility of the screwed connections (in built-up sections), the obtained results are complemented with those of the finite strip method and generalized beam theory formulations.

This paper presents a simplified stability-based method for practical structural predesign of down-aisle unbraced frames of selective racks. Given the uniformity of actual racks, only a single upright and its adjoining half beams were modeled, discretized with two-dimensional (2D) beam elements; the flexibility of the upright–beam and upright–floor connections was represented with linear springs. Such a model is used for linear buckling and second-order analyses. The proposed method consists of iteratively resizing the structural members according to cost and stability criteria (linear buckling analysis) until the serviceability limit state (SLS) and ultimate limit state (ULS) are satisfied (second order analysis). Specific procedures were developed to accelerate the computations. Two practical examples were analyzed to assess the performance of the proposed method. Compared with conventional design approaches for racks, the method was faster, and resulted in less-expensive structures. The simplification involved in the single-column consideration is sufficiently accurate. Some ideas about efficient methods of improving the stability of racks were presented.

This paper is the result of both experimental and numeric analyses on pallet rack components. Two cyclic testing protocols for beam‐end connectors of adjustable racking systems are compared; such experiments are named as “code type” and “Castiglioni”. Both protocols share the same test mock‐up: an assembly of a doubly‐pinned upright segment with a cantilever beam specimen. These tests consist in an up‐to‐failure increasing push‐pull process at the free beam end. In the “code type” test, the imposed displacement loops are centered around zero; conversely, in the “Castiglioni” tests, both upward and downward displacement segment runs are centered around a vertical static equilibrium situation (to take the gravitational load into account). The “code type” test is expected to result in a higher number of cycles than the “Castiglioni” one because of the two following features of the latter: (i) the gravitational load is always present, thus resulting in a higher demanding test, and (ii) the failure point is precisely predefined and usually produced before the total breakdown. This paper describes and compares experiments using both protocols. Additionally, these tests are numerically simulated.

A global analysis of a rack frame conducted using the Generalised Beam Theory (GBT) is presented. This study specifically focuses on a down-aisle frame, showing the particular characteristics of this type of structure, such as its perforated columns, semi-rigid joints, and significant second-order effects. The single-column simplified approach is applied, meaning that the entire rack is modelled with one single column and its adjacent half-beams. This approach substantially reduces modelling time and allows for very quick parametric studies while adequately reproducing the general 2D down-aisle behaviour. The GBT single-column model is first verified against a similar single-column shell finite element model used by the authors in previous research. Afterwards, the model is applied to study the effects of various factors influencing the results of a rack global analysis, including perforations, imperfection magnitudes and combinations, and sectional deformations. The nature of GBT allows for deriving clear conclusions on the influence of these aspects on structural behaviour. Furthermore, this article also aims to demonstrate the potential advantages of the theory for performing global analyses of these structures in both research and design.

This article presents a design method for the improvement of steel structures stability by modifying their structural elements parameters. The available parameters can be selected from a predefined list of stiffness and ultimate capacities for joints and steel members. The proposed procedure is based on determining the critical load factor (ratio between the critical and the demanding loads: α_cr = P_cr / P_Ed) and analyzing its sensitivity with respect to the design parameters, by using its gradient vector and Hessian matrix. The methodology is well suited for structures where the second order effects are relevant. A simple two parameter example is presented, and the general procedure for finite element analysis is outlined.