Estudo de conectores de cisalhamento formados por parafuso com cabeça sextavada e rebite tubular com rosca interna para pilares mistos em perfis de aço formados a frio e concreto

Abstract

This research presents a study of the behavior of bolts with hex head and tubular rivets with inner threads used for composite columns of cold-formed profiles filled with conventional concrete. The use of these materials as shear connectors is an innovative solution and it has a huge practical interest for situations in which a column is tubular, with cold-formed profiles. This interested can be attributed to three main reasons, such as: the connection execution facility when it has access only to the outside of the tube; the elimination of weld points at the connection, which avoid unexpected initial deformations and even a rupture in the region and lastly the possibility of using this connector as joint element between beam and column. To understand the context of the use of these connectors and the connectors in general, initially it will be defined the composite structures of steel and concrete and the advantages, disadvantages and the factors that affect the performance of this system. Following this, it will be presented the main studies conducted with bolts and with tubular rivets with inner threads as shear connectors. As the application of this connector for composite columns is a pioneering study, numerical studies with bolts as shear connectors will also be presented as basis for the theoretical part of this work. Next, it will be presented concisely, the experimental part of push-tests carried out in Structural Engineering Laboratory (LAEES) at UFMG in composite columns using the rivet connector and the bolt with hex head, and in more details, the numerical study, since the calibration to the parametric and analytic studies. Finally, it is proposing an analytical expression which can describe the resistant load of the connector, which can proves the use of this connector as technical, safe and economic solution