Um estudo da influência da inclinação de pinos em uma união híbrida metal-compósito

Abstract

One of the major challenges of aeronautics and aerospace industries is to optimize the relationship between weight and mechanical strength of structural components. In this sense, there is a great tendency to replace metallic elements by elements made of composite materials, considering that they have a lower density and demonstrate satisfactory mechanical resistance for specific applications. On the other hand, in some aeronautical sections, the use of metals is mandatory. With this, it is necessary the development of studies that seek to characterize and identify advances at the junctions between composites and metals. This study applied the concept of hybrid joints (mechanical and adhesive locking combination) to join surface treated steel sheets with fiberglass composite sheets, and allowed na evaluation the effect of locking pins inclination on mechanical behaviour. Through the CMT-PIN welding method, the pins were produced on the metal surface at three different inclinations and, subsequently, the glass fibers were deposited and laminated with the resin itself, serving as adhesive bonding and forming hybrid metal-composite joints after curing. Four test specimens from each inclination group were produced (in a total of twelve units) of which ten were tested and analyzed for: welding process, added mass, stiffness and strength. The results were compared with values presented in the literature for pins with no inclination. It was verified that there was no significant change of mass and and stiffness with the deposition of inclined pins on the samples. It has been observed that the benefit of pin inclination in hybrid joints is minor but it exists. It was noticed that pins inclined to 15o presented mechanical behavior superior to those inclined to25o and 35o. Possible reasons for not contributing to improve the mechanical performance of the hybrid joint with higher pin inclinations are presented.