Notional load method for industrial steel storage racks: Fid-Bau Portal

Notional load method for industrial steel storage racks

Sarawit, Andrew T. / Peköz, Teoman

AbstractThe discussion in this paper is on the stability analysis and design of industrial steel storage racks. Studies were carried out to evaluate the current Effective Length Method, and to examine the Notional Load Method as an alternative design procedure. Presently, the design of industrial steel storage racks in the United States is carried out according to the Rack Manufacturers Institute (RMI) specification using the effective length method. The notional load method is a new method for stability analysis and design of structural steel systems introduced in the AISC Specification for Structural Steel Buildings (ANSI/AISC 360-05). The difference between these two methods is that in the effective length method the beam-column member within the frame is designed based on effective member length while in the notional load method it is designed based on actual member length and the analysis is based on a reduced stiffness in the structure. The finite element method, which considers both geometric and material nonlinearities, was used as the basis for evaluating the accuracy of these two design methods. The study was carried out for numerous cold-formed steel industrial storage rack configurations. The application to cold-formed steel structures had to include the frequently encountered torsional–flexural buckling and semi-rigid joints. Results showed that the effective length method is more conservative than the notional load method and the notional load method agrees better with the finite element results than the effective length method does. It is, therefore, recommended that the notional load method be considered as an alternative means for industrial steel storage rack design.