Shake Table Testing of Standard Cold-Formed Steel Storage Rack

Ahmad Firouzianhaji,Nima Usefi,Peyman Mehrabi,Bijan Samali

doi:10.3390/app11041821

Ahmad Firouzianhaji, Nima Usefi + Show 2 more

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https://doi.org/10.3390/app11041821

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Abstract

Full-scale shake table investigations are strongly required to understand the actual performance of storage racks and to improve the rack design guidelines. This paper presents the results of full-scale shake table tests on New Zealand standard storage rack frames with two-bay and two-level to determine the dynamic characteristics of a standard rack structure and to measure the damping of the system. The experimental program was conducted in three phases. First, the identification parameters including the natural frequency and damping of the system were determined through a series of preliminary tests. Then, shake table tests were performed to capture the inelastic response of rack frames under low to medium intensities of El-Centro ground motion. Finally, the shake-table tests were repeated with scaling down the time domain and broader ranges of ground motion intensities to consider the performance of taller rack systems. In addition, a comprehensive discussion on the damping of the system is also provided based on the test results. The performance of the rack frame is described through an extensive set of measurements, including rack displacement, pallet sliding, the acceleration of a concrete block and rack frame and the damping of the system in the down-aisle direction. The results indicate that the standard rack frames are able to endure large inelastic deformations without loss of stability.

Highlights

Being part of the Pacific Ring of Fire, which is geologically active, New Zealand has experienced many large earthquakes in the past decades
Details of the experimental results of shake table tests on standard storage racks in the down-aisle direction were presented in this paper
To generate data on the seismic inelastic response of a standard rack system in New Zealand, a 2 level—2 bay frame was subjected to El-Centro earthquake records with different intensities in an increasing fashion from low to high intensities

Summary

Introduction

Being part of the Pacific Ring of Fire, which is geologically active, New Zealand has experienced many large earthquakes in the past decades. It was observed that, despite the basic assumptions for seismic design and stability analysis, “linear deformation of the frame” is not an accurate assumption and not all the connections experience the same rotation along the frame height (Figure 1b). The cyclic deterioration of such connections triggered a progressive collapse of all frames in the warehouse [1,2,3,4,5] (Figure 1d), which indicates that the current racking codes and specifications are still weak about the cyclic features of the connections

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