EMPLOYING 2D MATERIAL IN REINFORCING INTERFACE STRENGTH IN FIBER-REINFORCED METAL LAMINATES

Abstract

This study was conducted with the aim of improving fiber-metal laminates (FMLs) by strengthening the interface between layers using 2D materials such as the ɑ-Zirconium phosphate (ɑ-ZrP). The importance of this topic is emphasized by an analysis of the literature, which reveals a gap in research in the field of application of ɑ-ZrP nanomaterials. Even though ɑ-ZrP was discovered and synthesized a long time ago, there is a lack of studies in using it as a reinforcement for fiber metal laminates. To achieve this goal a research were conducted to synthesize and characterize ɑ-ZrP nanoparticles. Then some experiments were performed to find the best composition of the polymer starting from 0 wt% to 2 wt% of these nanoparticles by using the commercial polyurethane. Several single lap joint samples using the aluminum sheets were made and additionally pure polyurethane polymers were examined for the extra information about the adhesive layer. Mechanical and electrochemical treatments were implemented for the improvement of the interlocking mechanism between the metal and adhesive polymer. In addition, the synergetic effect of their combination with nanoparticles was studied. The behavior of the composite was studied using different testing types such as the single lap shear strength test and tensile strength test for pure polyurethane as well as it was analyzed by the Finite Element Analysis (FEA) using the ABAQUS software. Ultimate tensile strengths were determined for the comparison of the experimental and numerical parts’ results and the best concentration for the pure polymer was found to be 1.0 wt% of ɑ-ZrP with 3.5 times enhanced tensile strength, while for single lap joints it was 0.5 wt% which increased the shear strength by 91.8%. Mechanical treatment by itself significantly increases the shear strength of lap joints by 35%, although it reduces efficiency in combination with nanoparticles. Conversely, electrochemical treatment, especially combined with nano reinforcement showed superior performance in terms of increase of the shear strength by 174% compared to all other treatments. Although the combination of nanoparticles with both treatments provided a slight increase in strength by 18.9%, this did not correspond to the significant increase achieved by electrochemical treatment. The initial hypothesis was proved and supported with numerical modeling