Abstract
The weight and fuel savings offered by composite materials make them attractive not only to the military, but also to the civilian aircraft, space, and automobile industries. In these industries, bolted and riveted joints are extensively used as a primary method for structural joining. Bolted joints in composite materials have complex failure modes, and hence the demand for improving their performance exists. The main objective of this work is to improve the performance of bolted joints in composite structures by introducing nanoparticles/fibers around the expected failure zone. The literature on this issue showed shortcomings in the investigations of such materials. Most of the investigations in this field aimed to enhance the mechanical properties of epoxy materials, which cannot be used alone for high performance structural applications due to their low mechanical properties. In the present work, epoxy resin was modified with different types of nanofillers including multi walled carbon nanotubes (MWCNT). Nano-phased epoxy was used to fabricate different types of nanocomposites as well as nano-hybridized glass fiber reinforced composite laminates. Therefore, six different advanced materials were fabricated including a nanocomposite material (MWCNT/E), a quasi-isotropic nano-hybridized composite laminate (QI-GFR/MWCNT/E), a unidirectional nano-hybridized composite laminate (UD-GFR/MWCNT/E) and a control panel manufactured without nano-fillers (neat epoxy, QI-GFR/E, UD-GFR/E). The materials were characterized by tension and compression tests. The obtained properties are essential for the validation of respective finite element analysis. The results showed improvements in the tensile and compressive properties (strength and modulus) of the fabricated nanocomposites (MWCNT/E) compared with neat epoxy. The hybridized composite laminate with MWCNT showed high improvements in their mechanical properties compared to the composite laminates without nanofillers.