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

Abstract

In order to reduce the mass and therefore the fuel consumption, the aerospace industry have been implementing the use of composite materials in their airframes. However, there are few examples where the metals can be entirely replaced by composite materials. Therefore, when there are both materials (composite and metals) they must be joined to become one larger structure. In this line, hybrid advanced joining is one of several ways to achieve that and it is getting close attention over the past years. A more recent hybrid joining method is the combination of adhesive boding and small pin-like protuberances welded on the metal side by CMT-Pin process, that act holding the load on the composite side. Being recent, this hybrid joining method still demands further investigation and study. Therefore, the objective of this work is to study the influence of pin quantity in metal-composite hybrid joining. Samples with single lap joint configuration were fabricated with different amounts of pins by CMT-Pin welding and by manual lamination of fiber glass reinforced polymer and then tested under tensile/shear loading. The results showed that the samples containing intermediary quantity of pins had superior performance in terms of both strength and stiffness. However, a larger quantity of pins seems to avoid the proper adhesion between the composite and the surroundings of the pins, which drives to a performance similar to that of joints with no pins. As expected, the use of pins made by CMT-Pin welding does not increase the final mass of the components in a significant way, which reinforces the potential of this combined joining approach for lightweight structures typically found in the aerospace and other transport industries.