The low-velocity impact and bending performance of adhesive joints are critically important for their reliable use in multiple industrial applications. Enhancements of adhesive joints’ mechanical properties are significantly valuable for the long-term safe use and overall life of structural components. This study investigated the low-velocity impact and bending properties of double strap joints (DSJs) reinforced with graphene nanoplatelets (GNPs). In this context, GNP-reinforced adhesives with 1%, 2%, and 3% reinforcement by weight were prepared, and the dispersion quality of graphene was examined using scanning electron microscopy. Subsequently, graphene-modified DSJs were manufactured and mechanical tests were carried out. Low-velocity impact tests were performed at 5 J and 10 J energies in a single impact configuration. Tests of the nonperforated specimens showed that the contact force increased with graphene reinforcement. The absorbed energy and the contact time of the specimens with the impactor tip decreased with nano reinforcement by 5% and 4%, respectively. Additionally, a significant decrease in the displacement was observed with 2% and 3% graphene reinforcements. Significant improvements of up to 58% were observed in the flexural strength of the joints with graphene reinforcement.

This study performed an experimental modal analysis and investigated the mechanical properties of graphene nanoparticle (GNP)-reinforced, adhesively bonded double strap joints (DSJs). The DP270 structural adhesive was reinforced with graphene nanoparticles by using five different manufacturing methods and bulk specimens were prepared with 1%, 2% and 3% reinforcement by weight. The dispersion of graphene was observed by using scanning electron microscopy (SEM) because its efficient distribution in the adhesive is directly affected by the mechanical and modal properties of the modified polymer. Furthermore, the damping ratios and natural frequencies of the bulk specimens were also determined. Based on the dynamic characteristics and SEM observations, the most appropriate method to manufacture the joints was selected, and DSJs were prepared by using AA 2024-T3 aluminum alloy as the adherend. After that, the modal and tensile properties of the graphene-reinforced DSJs were determined. Consequently, it was observed that a graphene reinforcement ratio of 2% by weight showed a 36% increase in the damping ratio of the adhesive and a 23% increase in the damping ratio of the joint. In addition, it was observed that graphene reinforcement resulted in up to an 81% increase in the failure strength of the modified DSJs.

This study explores the effects of nanoclay addition on mechanical response of Glass/Carbon/Glass fiber (G/C/G) reinforced epoxy matrix composite laminates under tensile and flexural loadings. Organomodified nanoclay containing Glass/Carbon/Glass hybrid composite laminate was evaluated for dynamic mechanical properties as well as mechanical strength, stiffness and ductility. Two different types of fiber reinforced hybrid composites were manufactured. The amount of nanoclay additions were 0.75 wt % and 1.25 wt % with respect to epoxy resin and hardener. A nanoclay containing epoxy – Glass/Carbon/Glass hybrid composite laminate were manufactured by using a hydraulic hot press. Then, tensile, flexural tests and dynamic mechanic analysis (DMA) was implemented to ASTM standard specimens which were cut from the plates by using abrasive water jet cutter. Uniaxial tensile and three-point bending tests have been carried out to obtain some mechanical characteristics such Young’s modulus, tensile strength, break strain, flexural strength and modulus of the hybrid composites. DMA measurements also performed to compare nanoclay effect. The results of this study demonstrated that the mechanical behavior was positively affected by nanoclay addition into epoxy resin. The tensile strength and flexural strength significantly increased compared to the non-nanoclay hybrid composite (pure). However glass transition temperature (T g ) of hybrid composites decreased with increasing amount of nanoclay.

Hexagonal boron nitride (h-BN) has recently been utilized as a reinforcement in composite materials due to its properties such as hardness, thermal conductivity, electrical insulation, and strong chemical stability. The aim of this study is to investigate the effect of nano-sized hexagonal boron nitride (h-BN) on the mechanical properties of flax fiber-reinforced composite material. For this purpose, initially, hexagonal boron nitride was added to epoxy resin in different weight ratios and homogenized without agglomeration using ultrasonic treatment. Then, by employing the hand lay-up method, the mixture was applied to flax fiber fabrics and the flax fiber-epoxy composites were produced using the vacuum bagging method. Mechanical performance of the composites, produced with 0.5%, 1%, and 1.5% by weight of hexagonal boron nitride, was determined through tensile, flexural, shear, and compression tests. Experimental results indicated that the addition of hexagonal boron nitride to flax fiber epoxy composite material increased the flexural strength and modulus compared to the unreinforced flax fiber epoxy composite material. The highest flexural strength and modulus were observed in the samples with 1.5% by weight of hexagonal boron nitride (h-BN). Consequently, it can be considered that flax fiber-epoxy composite material with hexagonal boron nitride (h-BN) addition holds potential, especially for applications subjected to bending moments.

Due to its high pore size and low density, amine‐modified silica aerogel (XSA) is an excellent candidate for the secondary reinforcement material of polymer matrix composites. In this study, the mechanical, thermal, and morphological properties of amine‐modified silica aerogel‐reinforced aramid/epoxy composite (EAFS) produced by the hand lay‐up method were investigated. According to the resin weight, 1 wt.% (EAFS‐1), 2 wt.% (EAFS‐2), and 3 wt.% (EAFS‐3) XSA reinforcements were dispersed into the epoxy resin by ultrasonic mixer. Tensile, three‐point bending, compression, and shear tests were performed to determine the mechanical properties, while thermal properties were determined by dynamic mechanical analysis and thermogravimetric analysis. The mechanical properties demonstrated an upward trend up to EAFS‐2, after which a decline was observed at EAFS‐3. Tensile strength, modulus of elasticity, flexural strength, flexural modulus, and compressive strength of EAFS‐2 increased by 20.43%, 30.91%, 10.09%, 24.01%, and 3.62%, respectively, compared to EAFS‐0. Furthermore, the incorporation of XSA reinforcement resulted in a delay in the onset and endset of the degradation temperature.