Effect of Shape Memory Alloy Wires on the Buckling Behavior of Fiber Metal Laminates

R. Eslami-Farsani,M. R. Mohaseb Karimlou,A. Saeedi,A. Zamani 한국섬유공학회 2019 Fibers and polymers Vol.20 No.8

Buckling behavior of shape memory alloy (SMA) reinforced fiber metal laminates (FML) was experimentallyinvestigated. The SMA reinforced FML specimens with three different pre-strain levels (1, 2 and 3 %) and different numberof the embedded wires (2, 4 and 6 wires) were prepared by a specific mold and hydraulic pressure. The effects of the appliedpre-strains in the SMA wires, as well as the stacking sequence of the laminate, SMA volume fraction and the location of thewires were studied on the axial and lateral force-displacement diagrams for the specimens during buckling tests. According tothe results, 53 % enhancement in the buckling load was obtained for 2 SMA wires reinforced FML specimens in comparisonwith the specimens without embedded SMA wires. In constant volume fraction of the SMA, pre-straining the wires by 3 %led to 25 % improvement in the buckling load, in comparison with the specimens reinforced with 1 % pre-strained wires. Theinfluence of the FML stacking sequence on the results was also discussed.

Zinc-doped sulfonated polyaniline tailored Multi-walled carbon nanotubes (Zn-SPANI-MWCNT); A novel nano-hybrid for designing a smart self-healable epoxy coating

Hamid Jalali,Reza Eslami-Farsani,Bahram Ramezanzadeh 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.122 No.-

In this study, the oxidized carbon nanotubes (MC) were functionalized with sulfonated polyaniline (SPi)and Zn cations (Z) via a layer-by-layer (LBL) method. The characterization of MC particles with and withoutinhibitors was done by Fourier-transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD),Thermogravimetric analysis (TGA), and Field emission scanning electron microscopy (FE-SEM) methods. The active–barrier corrosion protection abilities of the coatings loaded with MC, MC.SPi, and MC.SPi.Znano-carriers were evaluated by electrochemical impedance spectroscopy (EIS). The recorded log jZjmagnitudesat low frequencies for the MC.SPi.EP and MC.SPi.Z.EP samples were higher than 10, which illustratedthat the loading of inhibitors on the MC could improve the distribution of nano-carriers in thecoating and enhance the barrier index and stability of the coating. The EIS results attributed to thescratched coatings revealed that the MC.SPi.Z.EP total resistance was almost 8 times higher (83000ohm.cm2) than the EP sample even after 72 hours. Higher adhesion and less penetration of corrosiveagents into the interface of metal and coating were shown by pull-off and cathodic separation tests. Inthe cathodic separation test, the delamination of MC.SPi.Z.EP sample is reduced to 68% compared toEP, and also the pull-off strength is improved to 52%.

Evaluating the Mechanical Behavior of Basalt Fibers/Epoxy Composites Containing Surface-modified CaCO3 Nanoparticles

Arezoo Abdi,Reza Eslami-Farsani,Hamed Khosravi 한국섬유공학회 2018 Fibers and polymers Vol.19 No.3

Polymer matrix composites (PMCs) owing to their outstanding properties such as high strength, low weight, high thermal stability and chemical resistance are broadly utilized in various industries. In the present work, the influence of silanized CaCO3 (S-CaCO3) with 3-aminopropyltrimethoxysilane (3-APTMS) coupling agent at different values (0, 1, 3 and 5 wt.% with respect to the matrix) on the mechanical behavior of basalt fibers (BF)/epoxy composites was examined. BFreinforced composites were fabricated via hand lay-up technique. Experimental results from three-point bending and tensile tests showed that with the dispersion of 3 wt.% S-CaCO3, flexural strength, flexural modulus, tensile strength and tensile modulus enhanced by 28 %, 35 %, 20 % and 30 %, respectively. Microscopic examinations revealed that the development of the mechanical properties of fibrous composites with the incorporation of modified CaCO3 was related to enhancement in the load transfer between the nanocomposite matrix and BF as well as enhanced mechanical properties of the matrix part.

An Experimental Study on Impact Resistance of Different Layup Configuration of Fiber Metal Laminates

Mohsen Mirzaee Sisan,Reza Eslami-Farsani 한국섬유공학회 2019 Fibers and polymers Vol.20 No.10

Fiber metal laminates (FMLs) are composed of thin metal sheets and fiber-reinforced composite layers. Comparedto monolithic aluminum alloys, FMLs combine lower density, higher fatigue resistance, and improved damage tolerance. Thepresent study aimed to investigate the low-velocity impact induced by drop-weight instrument and the tensile strength onvarious lay-up configurations of FMLs fabricated. FML samples were composed of two layers of aluminum 2024-T3 and twolayers of epoxy resin, which were reinforced with carbon fabric, glass fabric, and Kevlar fabric made in pairs. In addition,another type of FMLs was developed with carbon/Kevlar fabric under the same circumstances. Force-time histories of impactforces were recorded, and the damaged specimens were inspected using optical microscopy in terms of the impact side, nonimpactside, and cross-sectional side. Experimental results indicated that the maximum impact force corresponded to theFMLs that were composed of Kevlar fabric on the impact side and glass fabric on the non-impact side. In addition, thehighest tensile strength and Young's modulus among FMLs belonged to FML with Kevlar fabric and glass fabric.

High Velocity Impact Response of Aluminum- Carbon Fibers-Epoxy Laminated Composites Toughened by Nano Silica and Zirconia

Hossein Rahmani,Reza Eslami-Farsani,Hossein Ebrahimnezhad-Khaljiri 한국섬유공학회 2020 Fibers and polymers Vol.21 No.1

This research work investigated the effects of SiO2 and ZrO2 nanoparticles type and content incorporated into anepoxy matrix on the high velocity impact behavior of carbon fiber reinforced aluminum laminates (CARALL). CARALLspecimens consisted of a 0/90/90/0 stacking sequence of a carbon-epoxy composite containing 0, 1, 3, 5 and 7 wt% of each ofnanoparticles sandwiched between two layers of aluminum 2024-T3. To observe the toughening effects of the nanoparticleson the fracture surface of the impacted CARALL, a typical field emission scanning electron microscope (FESEM) wasemployed. Impact energy absorption of CARALL was at most increased by 18 % and 12 % with the nanoparticles content of5 wt% SiO2 and 3 wt% ZrO2, respectively. Overloading of the nanoparticles content up to 7 wt% resulted in the creation ofnanoparticles aggregated sites associated with loss in the energy absorption capacity. FESEM fractography procedure alsoshowed that the crack deflection and pinning were the most recognizable toughening mechanisms exhibited by nanoparticles. Overall, the controlled addition of SiO2/ZrO2 rigid nanoparticles to CARALL was found to be a promising method forimproving the high velocity impact energy absorption of CARALL.

Investigating the High Velocity Impact Behavior of the Laminated Composites of Aluminum/Jute Fibers- Epoxy Containing Nanoclay Particles

Hossein Ebrahimnezhad-Khaljiri,Reza Eslami-Farsani,Saeid Talebi 한국섬유공학회 2020 Fibers and polymers Vol.21 No.11

In this research work, the effect of adding nanoclay on the high velocity impact behavior of fibers metal laminates(FMLs) of aluminum- Jute fibers/epoxy was investigated. To do so, the nanoclay particles with different percentages (0, 1, 3and 5 wt.%) were firstly added into the epoxy matrix. In the following, the FMLs with the configuration of 0/90/0/90/0 weremade by hand lay-up method. After that, the fabricated samples were tested by high velocity impact test. In order toinvestigate the effect of nanoparticles on the impact properties, the field emission scanning electron microscope (FESEM)was used. The obtained results showed that the samples with 0, 1, 3 and 5 wt.% had the limit velocity of 81.9, 83.7, 87.4 and85.4 m/s, respectively. The limit velocity increment in these samples by adding nanoclay were 2.2, 6.7 and 4.3 %,respectively. Also, the obtained results showed that by adding the 1, 3 and 5 wt.% nanoclay, the absorbed energy wasimproved about 4.5, 14 and 8.8 %, respectively. The sample with 3 wt.% nanoclay had minimum delamination lengthbetween aluminum shell and composite core, which was due to the effect of nanoclay in the interface adhesion of core-shell. The microscopically analysis showed that the nanoclay increased the fibrillation of Jute fibers as one of the absorbed energymechanisms in the Jute fibers. Also, the agglomeration phenomenon in the sample with the 5 wt.% nanoclay was illustrated,which was the decreasing factor of its impact properties, as comparison with sample with 3 wt.% nanoclay.

Investigation of Longitudinal and Transverse Reinforcing Single Lap Joints of the Polymer Composites/Al under Hygrothermal Condition

F. Jafari,R. Eslami-Farsani,S.M.R. Khalili 한국섬유공학회 2020 Fibers and polymers Vol.21 No.10

In this study, the effect of longitudinal and transversal reinforcing of epoxy based carbon fiber reinforcedcomposite/Al (CFRP/Al) and glass fiber reinforced composite/Al (GFRP/Al) single lap joints (SLJs) by using of pins andwires has been investigated under hygrothermal conditions. Overall three sets of specimens for each composite/Al joint weremanufactured which consist of single lap joint (SLJ), single lap joint reinforced with 6 steel pins of 1 mm diameter intransverse direction (SLJP) and single lap joint reinforced with wires of diameter 0.2 mm, in longitudinal direction (SLJW)for CFRP/Al and GFRP/Al adherends. The tensile properties of the samples were measured after 500 and 1000 hrs. inhygrothermal conditions of 70 ºC, relative humidity of 85 % and compared corresponding to unheated samples. The resultsshow that using of pins, increases the tensile strength by 14 % in GFRP/Al and 13.7 % in CFRP/Al SLJs. Also wire increasedthe tensile strength of the SLJs by 26 % in GFRP/Al and 19 % in CFRP/Al SLJs. Hygrothermal conditions decreased thetensile strength of both GFRP/Al and CFRP/Al SLJs samples, where the highest degradation was observed in simple GFRP/Al SLJs (34.45 %) and the lowest was in wire reinforced CFRP/Al SLJs (21 %). Overall it could be concluded that wires andpins increases the lifespan of both CFRP/Al and GFRP/Al SLJs under hygrothermal conditions.

The Simultaneous Effect of Microcapsules and Silica Nanoparticles on the Mechanical-healing Properties of Glass Fibers-Epoxy Smart Composites

Hossein Ebrahimnezhad-Khaljiri,Reza Eslami-Farsani,Sadegh Mirzamohammadi,Shabnam Arbab Chirani 한국섬유공학회 2022 Fibers and polymers Vol.23 No.10

The aim of this study is to assess the simultaneous effect of incorporating capsulated healing agent and silicananoparticles on the mechanical-healing behaviors of glass fibers/epoxy composites. To do so, the 14 wt.% capsulated epoxyhealing agent by urea-formaldehyde polymeric shell and the various percentage of silica nanoparticles (1, 3 and 5 wt.%) wereadded into the glass fibers-epoxy composites for studying the healing behavior under the tensile and flexural conditions. After the damaging and healing processes of composites, the maximum healing efficiency in flexural strength (110.7 %) wasseen in the composite containing 5 wt.% silica nanoparticles. But the highest healing efficiency in the tensile strength(64. 2%) belonged to the smart composite with 3 wt.% silica nanoparticles. The silica nanoparticles improved the recoverycapability of mechanical properties by changing the damage modes into the smart composites. Filling the micro-voids andreducing the effect of agglomerated nanoparticles by healing agent were the effective mechanisms, which improved themechanical recovery capability. The other observed phenomena by field emission scanning electron microscope wereimproving the adhesion between glass fibers and epoxy, creating the micro-voids by silica nanoparticles, wasting the crackpropagation energy by stick-slip method and reducing the flow ability of healing agent by silica nanoparticles.

The Effect of Different Configurations on the Bending and Impact Properties of the Laminated Composites of Aluminum-Hybrid Basalt and Jute Fibers-Epoxy

Nabiollah Zareei,Abdolreza Geranmayeh,Reza Eslami-Farsani 한국섬유공학회 2019 Fibers and polymers Vol.20 No.5

In this work, the effect of different stacking sequences of hybrid jute (J) and basalt (B) fibers-epoxy compositeslaminated by aluminum (Al) 2024-T3 on the bending and impact properties of them was investigated. To do so, firstly, thejute fibers and aluminum surfaces were modified by the chemical methods. Then, four hybrid composites laminated byaluminum sheets were fabricated; these were Al/J/J/B/B/J/J/Al, Al/B/B/J/J/B/B/Al, Al/J/B/J/B/J/B/Al and Al/B/J/B/J/B/J/Al. The obtained results showed that the Al/B/B/J/J/B/B/Al composite had the maximum flexural modulus, strength and impactenergy, which were 520 MPa, 41.2 GPa and 9.55 J, respectively. In contrast, the Al/J/J/B/B/J/J/Al composite had theminimum flexural modulus and strength, which were 252 MPa and 31.1 GPa, respectively. Also, Al/J/B/J/B/J/B/Al had theminimum impact energy of 4.75 J. As the most important finding obtained in the microstructure investigations, it wasrealized that the adhesion between the basalt fibers and the aluminum sheet was the important factor improving themechanical properties.

High Velocity Impact Response of Basalt Fibers/Epoxy Composites Containing Graphene Nanoplatelets

E. Kazemi-Khasragh,F. Bahari-Sambran,M. Hossein Siadati,R. Eslami-Farsani 한국섬유공학회 2018 Fibers and polymers Vol.19 No.11

The effects of adding surface modified graphene nanoplatelets (GNPs) in various weight percentages (0, 0.1, 0.2, 0.3, 0.4, 0.5 with respect to matrix) on the high velocity impact response of basalt fibers/epoxy composites were evaluated. High speed mechanical stirrer and ultrasonic waves were used for the dispersion of GNPs in the epoxy matrix, and hand layup method was utilized for the fabrication of the composite samples. High velocity impact testing was performed using a conical projectile. The results demonstrated that the maximum improvement in the impact limit velocity and energy absorption occurred in the 0.3 wt.% GNPs nanocomposite, i.e., 11 and 23 %, respectively. Also, the electron microscopy studies revealed that the addition of GNPs contributed in improving the impact properties by influencing the matrix and thus enhancing the interfacial characteristics between the basalt fibers and the matrix.