Investigation of Seismic Behaviour of Steel Pallet Rack Frames

Abba Mas’Ud Alfanda

doi:10.11648/j.ajetm.20170202.12

Abstract

One of the most significant uses of cold-formed members is for steel storage racking structures, such as pallet, drive in, and drive through racking systems. In the current competitive industry, pallets and storage racks may support heavy loads that have the potential to injure workers and damage equipment if the pallets and racks fail and loads fall. Hence, storage racks must remain structurally sound. Additionally, when subjected to earthquake loading, they can exhibit very large transverse displacement. In spite of their complexity, racks are able to carry heavy loads, though they are designed as lightly as possible, and industries often rely on 3-dimensional Finite Element Analysis to achieve this objective. This study, presents a Finite Element model of a conventional rack structure modeled using the commercial software SAP2000. In order to investigate the seismic behaviour of rack frames under real earthquake ground motions, the Time History Analysis was performed with rigid, semi-rigid and pinned connections. The study provided a strong case for the possible benefits of semi-rigid steel frames and motivated the need for detailed, accurate, and reliable analytical models of the connection. Neglecting semi-rigidity cause stiffening of frames resulting in shorter fundamental period and larger lateral displacement which in turn results in a significant error in the evaluation of dynamic loads.

Highlights

One of the most significant uses of cold-formed members is for steel storage racking structures, such as pallet, drive in, and drive through racking systems [3]
The main aim of the study is to investigate the range of response characteristics of pallet rack frames, having different connection types subjected to seismic loading
There is no apparent difference between Case 1 and Case 2 in terms of period of vibration for all the three connection types considered. These results provide confirmatory evidence that load case 2 cannot be considered as the critical loading contrary to the FEM 10.2.02: (The Design of Static Steel Pallet Racking) as such static and dynamics design cannot be treated in the same way

Summary

Introduction

One of the most significant uses of cold-formed members is for steel storage racking structures, such as pallet, drive in, and drive through racking systems [3]. Storage racking systems are as well differentiated by the great variety of typologies, shapes and sizes, ranging from large warehouses to small shelves for offices or shops. This imposes different importance from a design point of view, and a somewhat incompatible situation regarding which design codes to use and when to use them. Their behavior is influenced by the geometry of their structural components (high slenderness elements, open section profiles prone to buckling problems) as well as by the nonlinear behavior of their joints (beam-to-upright and baseplate). Many difficulties arise in the prediction of their structural behavior or modeling problems of beam-to-upright and base-plate connections [23]

Objectives

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Discussion

Conclusion