Estudo da ligação de nós de treliça de madeira com fibra de carbono

Abstract

Civil construction is an area of Engineering that is constantly evolving to help solve problems, one of which is the corrosion of metal structures in places with high salinity, which required the development of new materials and construction methods. In this sense, this study arose from the need to find an alternative technique to make the connection between wooden truss elements when exposed to maritime environments and industrial areas, since traditional metallic connectors are susceptible to corrosion in these environments, which would lead to to a reduction in the reliability of the structure. Therefore, this work was developed with the objective of analyzing — based on a literature review, carrying out experimental tests and through computer simulation — the feasibility of using carbon fiber fabric and epoxy resin to connect the truss nodes. made of wood, replacing metal connectors. To this end, tests were carried out with triangular wooden prototypes of the species Eucalyptus cloeziana with the ends of the elements glued with carbon fiber and epoxy resin. The specimens were subjected to axial forces from a hydraulic press with a capacity of 15 tons, in which the displacement values of the upper node of the triangular structure were recorded at each stage of the tests. From this, it was possible to calculate the rotational stiffness parameter (Kθ), which was used in the computational analysis using the Finite Element Method (FEM). In the computer simulation, the rotational stiffness (Kθ) found was adopted to simulate the use of carbon fiber with epoxy resin in the truss connections. As a result, it was observed that the compressive and tensile strength stresses and the maximum displacement of the span were within the requirements required by NBR 7190 (2022). Thus, the application of the proposed technique for connecting the nodes of a wooden truss with carbon fiber and epoxy resin proved to be viable and safe as it meets the limit states required by the Standard, and can be an alternative against external environmental corrosion, to reduce the weight of the structure and improve the cost-benefit ratio in the development of Civil Engineering projects.