Hybrid effect of carbon nano‐fillers on the interlaminar fracture toughness of fiber metal laminates

Fiber metal laminates (FMLs) are a hybrid composite material used in aircraft structural parts. They are fabricated by stacking thin aluminum sheets with a fiber-reinforced polymer composite. In this research work, nanosilica was mixed with epoxy resin in different weight percentages such as 0, 1, 3, 5, and 7 wt% for the preparation of FML. Nanosilica was used as a secondary reinforcement in the epoxy resin to improve the interfacial bonding and mechanical strength of the FML. The morphology and chemical compositions of the cured nanosilicadispersed epoxy resin and aluminum were examined using Fourier transform infrared spectroscopy, X-ray diffraction, field-emission scanning electron microscope, and energy-dispersive X-ray analysis. Thermogravimetric analysis was used to investigate the thermal stability of epoxy before and after the addition of nanosilica. FML was prepared using the hand layup and compression molding processes by sandwiching thin aluminum alloy sheet and E-glass fiber. The FML specimens were cut using an abrasive water jet machine as per ASTM standards for determining their mechanical characteristics such as tensile strength, flexural strength, and short-beam strength. Vibrational analysis was undertaken, and the natural frequency and damping factor for the FML specimens were determined.The results revealed that the tensile strength of pure FML was increased by 7% for 3 wt% nanosilica-dispersed FML. Flexural and interlaminar shear strength was increased by 30.5% and 10.9%, respectively for the 1 wt% nanosilica-dispersed FML was compared to pure FML.

Section: Introductionmentioning

confidence: 99%

Comprehensive characterization of AA 2024T3 fiber metal laminate with nanosilica‐reinforced epoxy based polymeric composite panel for lightweight applications

Vijayan¹,

Selladurai²,

Balaganesan

et al. 2022

“…This stick-slip phenomenon during crack propagation is especially observed in FRP composites with woven fiber mats that bring about deflections in the crack path due to their non-planar surface and also due to the variations in the toughness of the matrix at the interlaminar region. 46 The stick-slip phenomenon could also be attributed to crack hindrance due to nanofiller and some bridging mechanisms such as fiber, tow and ply bridging. 47,48 The critical strain energy release rate (G IC ) values for all the FMLs were calculated; the G ini IC values have been plotted in Figure 9B, and the G IC propagation values (Rcurves) have been plotted in Figure 9C.…”

Section: Mode I Ilft Testmentioning

confidence: 99%

Enhanced interlaminar mechanical behavior of advanced fiber metal laminates via nano Al₂O₃‐IPN formation and surface pre‐treatments

Patnaik

Dasari

et al. 2023

The inferior delamination resistance and out‐of‐plane performance of fiber metal laminates (FMLs) are of serious concerns. This work employs two modification methods, namely metal surface's chemical pre‐treatment and nano Al2O3 embedded interpenetrating polymer network (IPN) formation for improving the delamination resistance of aluminum and glass fiber‐reinforced polymer (GFRP) composite‐based FMLs. The synergetic effect of the two modification techniques resulted in high degrees of improvement in delamination resistance that were ~28% for critical strain energy release rate during mode‐I interlaminar fracture toughness (ILFT), that is (GIC) and ~37% for GIIC. Simultaneously, the flexural strength, tensile strength, and interlaminar shear strength improved by ~23%, ~17%, and ~24%, respectively. Scanning electron microscopy, atomic force microscopy, and surface energy measurement studies showed that the chemical pre‐treatment significantly influenced the surface morphology, surface roughness, and surface energy responses of aluminum, respectively. Fractographic study validated the effect of modification methods on the failure behavior under various testing modes.

“…In low-velocity impacts, the absorbed energy also includes the bending deformation and delamination energy. Due to the brittle nature of the composite, the majority of energy was absorbed by fiber breakage, with the impact absorbing the remaining energies (such as global deformation, delamination, and shear-out energy) [38] The impact's outward area in each case was essentially the same. The most notable difference was that the holes in the composites generated at higher molar CuO concentrations were shaped like arches.…”

Section: Fractured Surface Topographymentioning

confidence: 99%

Improvement of interfacial adhesion of CuO nanostructured carbon fiber reinforced polymer composites

Shankar

Bajpai

2022

Hydrothermal technique was used to deposit copper-oxide (CuO) nanostructures on woven carbon fibers (WCF) to produce a nanostructured interphase that increased the interfacial strength with an epoxy resin matrix. In order to create laminated hybrid composites, CuO-modified WCF was reinforced with mixture of bisphenol-A epoxy resin and dimethyl aniline hardener as matrix using the vacuum bagging approach. Enhanced mechanical qualities are the result of increased volume fraction of CuO nanostructures, where the void content is minimal. The mechanical characteristics such as impact strength and tensile strength of CuO-coated WCF reinforced epoxy resin composite samples were assessed using drop-down impact test and universal material testing system. The outcomes demonstrate a considerable improvement in impact energy absorption (74.8%), elastic modulus (52%) tensile strength (42%) and in-plane shear strength (32%) for the CuO-coated WCF reinforced epoxy resin composites. This work demonstrates that the development of CuO nanostructures can lessen composite delamination and enhance composite performance because of the increase in interfacial surface area between the matrix and the fiber by CuO nanostructures potentially expanding the spectrum of structural applications for these materials.