Comportamento de conector em chapa com recortes retangulares aplicado em pilar misto tubular de aço preenchido com concreto

Abstract

In this work, an experimental and numerical study was carried out on shear connectors behavior produced from steel plates with regular rectangular cutouts (RT) when applied to concrete-filled steel tubular columns (CFST). The behavior of these connectors was evaluated in terms of stiffness, ductility, strength and through the observed failure modes. The experimental program comprised the standard push test (according to EN 1994-1-1:2004) of 10 CFST specimens (filled with conventional concrete) with two RT connectors, the load being applied only to the tubular profile and only the core supported on the base. The specimens differed from each other in terms of the shape and size of the tube and the use or not of steel reinforcement in the concrete core. Calibration of the numerical model was carried out through simulations of experimental specimens using the Abaqus finite element software. Around 160 models (including numerical and experimental examples) were studied in order to understand the connection failure mechanism. At the end of the work, it was verified that the failure mode occurred in a mixed way in the connection, with the connector showing large deformations (corresponding to the steel ultimate strength) in the critical section of all steel dowel or at least in the frontal steel dowel, accompanied by significant concrete compressive and tensile damage in the concrete volume surrounding the connector (mainly to the concrete dowels). Based on these results, an analytical model was proposed for the design of connectors with rectangular cutouts (RT) applied in CFST.