Análise teórico-experimental de colunas curtas em perfis formados a frio de seção transversal tipo rack

Abstract

The assembly facility, flexibility and diversity had made with that the storage racks systems to be widely used in Brazil. These systems normally consist of cold-formed steel members, and the connections of these are made by semi-rigid links, with bolts or not. Its columns are usually open thin walled perforated to accept the rabbet with other members. The design codes of cold-formed steel structures do not could be apply for racks systems for several reasons: verification of global stability, effect of the out-of-plumbness, horizontal and vertical imposed accidentally by transport equipments and the influence of perforations in the columns load capacity. Due these particularities, some manufactures have developed specific procedures for structural verification and design of these systems. The Storage Equipment Manufactures Association (SEMA, England, 1980), the Rack Manufactures Institute (RMI, USA, 1997) and Federation Européene de la Manutetion (FEM, 1996), applied in England, United States and Europe, respectively, are examples of specification developed for design of racks. In this work, experimental analysis in short columns with section had been carried through rack sections with different thicknesses, with and without holes, in order to evaluate the influence of the perforations in the load capacity and the deformations suffer during the test. The experimental results of perforated columns had been compared with RMI procedure and the proposed equation by Sarawit and Peköz (2003). Already for columns without holes, the association was made between the American and Brazilian codes for cold-formed steel structures. And, finally, is considered a new formulation to apply the NBR 14762 to perforated columns, using the effective area design by RMI.