Among the various types of industrial solutions used to store goods and products, the light duty hand loaded shelving rack (SR) typology represents a very popular solution for domestic applications, libraries and for superstores/markets open to the public. Despite the limited cost, an eventual collapse could result in significant damage of stored goods, injuries, and potentially the loss of human life, with the possible consequence of a long suspension of commercial activities. This reflects directly on the great importance of a correct design that, despite the large use of SRs, is nowadays developed with approaches characterized by inadequate levels of reliability. A research program on SRs is currently in progress in Italy, with the aim of improving the rules for both static and seismic design and this article presents a combined experimental-numerical study. Both component and pushover tests have been carried out, that are shortly summarized. Overall frame response has been simulated by means of advanced finite element software able to capture key features of the nonlinear response of slender frames with mono-symmetric cross-section members

Thin-walled cold-formed (TWCF) profiles are extensively used in adjustable selective pallet racks that represent the most common typology between the logistic solutions. In these structures, vertical members (uprights) are usually channels, often provided with intermediate stiffeners, rear flanges and additional lips. Furthermore, in order to allow for a rapid connection with beams and bracing components, usually uprights present regular perforation systems along their length. Nowadays, theoretical approaches available to design TWCF members are based on equations valid only for few unperforated (solid) cross-section geometries. As a consequence, rack manufacturing engineers frequently adopt the well-known design-assisted-by-testing approach to overcome this limitation and to assess accurately member performance. This approach, time consuming and cost demanding, stresses the need of further improvements required to cover aspects currently not considered in design codes.The paper summarizes the results of a study focused on the response of a commercial upright profile.In particular, 48 compression and 24 bending tests on perforated and unperforated profiles have been carried out. A summary of the experimental program is proposed together with the reelaboration of test data. Furthermore, the influence of perforation is discussed as well as key design geometric parameters. Finally, owing to the lack of information in major rack standard codes, three different proposals to evaluate the effective second moments of area have been developed, discussed and applied, hoping to contribute to standard improvements.

Steel storage pallet racks are framed steel structures commonly used in the logistic field. According to the European practice, they are built with cold-formed steel profiles. Vertical and horizontal elements are connected with mechanical joints and special elements are used for the base connections. The design of these structures is usually performed by adopting the 'design by testing' approach. This procedure asks for the experimental characterization of the main racks components and sub-assemblies, which allows identifying the parameters needed for the safety checks and the development of reliable FE models. Recent seismic events clearly showed the need for improvements in the knowledge of the seismic response not only of the components but also of the whole structure. As a contribution to this topic, an experimental study of the seismic response of full-scale rack frames is currently in progress. At this aim, a testing set-up for full-scale structures, with a maximum height of 22m, was designed and realized. In this paper, the main features of the experimental set-up and the results of two push-over tests on a commercial two-bay four-level pallet rack are described and discussed. Finally, the results of FE analyses are presented.

The strategies worldwide adopted nowadays for static and seismic rack design are based on approaches efficiently developed for the traditional carpentry frames, i.e. realized with hot-rolled bi-symmetric cross-section profiles. An open question is hence related to the effective degree of safety of these design rules when applied to racks, i.e. to structures realized by means of thin-walled cold-formed members, highly sensitive to second order effects. A study is currently in progress to define reliable seismic design procedures accounting for rack key features. In the framework of different planned activities, an ad hoc experimental equipment for testing full-scale racks under variable load conditions was developed. This paper presents the key features of the testing set-up, equipped with independent dynamic actuators, which allow applying vertical and horizontal loads.