SiO nanoparticle modified CFRP composites effecting on mechanical and vibration damping properties

Tetraglycidyl diamino diphenyl methane (TGDDM) and its carbon fiber composite are widely studied and used because of their heat resistance and high performance. In order to obtain efficient reinforcing effects in a simple manner, we adopt the idea of molecular composite—uniformly dispersing the rigid‐rod macromolecules in the TGDDM matrix. Herein, we prepared fully aminated‐poly(p‐phenylene terephthalamide) by direct polycondensation and hydrogenation reduction as the reinforcing agent. The fully aminated‐PPTA is distributed uniformly in the cross‐linked epoxy resin (EP) network by chemical bonds, and achieves efficient reinforcement. With the addition of only 0.5 wt% fully aminated‐PPTA, the tensile strength and Young's modulus of EP are improved to 127.7 ± 7.4 MPa (+28%) and 3.36 ± 0.15 GPa (+44%); the flexural strength and modulus are improved to 209.6 ± 9.4 MPa (+42%) and 3.70 ± 0.14 GPa (+37%); the notch impact strength is improved by 32%. Crucially, the heat resistance of EP almost remains unchanged. Furthermore, the flexural properties and interlaminar shear strength of the carbon fiber composite are also comprehensively increased. Compared with other modified fillers, the fully aminated‐PPTA is simple to prepare and blend, and is an efficient reinforcing agent for TGDDM and its carbon fiber composite benefitting from its rigid‐rod main chain and amino side groups.Highlights Molecular composite can achieve excellent strengthen and toughen effects. Fully aminated‐PPTA is embedded uniformly in EP network by chemical bonds. TGDDM is effectively reinforced without deteriorated heat resistance. Fully aminated‐PPTA is also a comprehensive reinforcement for EP/CF composite.

Fully aminated rigid‐rod aromatic polyamide efficiently reinforces tetraglycidyl diamino diphenyl methane epoxy resin and its carbon fiber composite

Wang,

Peng,

Wang

et al. 2024

Buckling characteristics of nano‐silica doped carbon fiber reinforced composites having cutouts

Özdemir,

Özbek,

Bozkurt

et al. 2024

Self Cite

The current study presents an experimental investigation devoted to the nano‐silica and cutout effects on the axial and lateral buckling responses of carbon/epoxy fiber‐reinforced composite laminates. To this end, specimens manufactured by vacuum bagging after hand layup technique were prepared at various amounts of nano‐silica (0.5%, 1.0%, 1.5%, 2.0%, and 3.0% by weight) incorporated into epoxy resin. Furthermore, semi‐circular and circular cutouts were opened on specimens to understand cutout effect on buckling characteristics of specimens. The results demonstrated that nano‐silica had a significant effect on buckling behaviors of the carbon fiber‐reinforced composites. Regardless of cutout presences, maximum critical axial (393.33 N, 361.67 N, 320 N for W, C and S) and lateral buckling loads (34.67 N, 33 N, 32.33 N for W, C and S), were achieved from the samples having 1.5 wt. % nano‐silica. In specimens having no cutout, maximum improvements of 72.26% in axial and 48.6% in lateral directions were achieved from the specimens having 1.5 wt. % nano‐silica content. A further amount of nano‐silica addition decreased the resistance to buckling of the specimens. Also, the presence of cutouts on the specimens led to decreases in critical loads. The decreases of 1.5 wt. % nano‐silica doped specimens without cutout in the axial and lateral critical buckling loads, respectively, were seen as 22.9% and 7.24% for circular cutout, 8.75% and 5.06% for semi‐circular cutout. It was concluded that cutout processing and nano‐silica additions should be taken into consideration in a material that may be exposed the buckling failures.Highlights Nano‐silica impact on buckling behaviors of carbon fiber‐reinforced composites Cutout effects on buckling properties of carbon fiber‐reinforced composites Failure modes of carbon fiber‐reinforced composites with nano‐silica particles Findings showed that 1.5 wt. % nano‐silica inclusion exhibited the best values for buckling.

Analysis of mechanical and vibration properties of carbon fiber reinforced polymer matrix composites with SiO₂/Al₂O₃ micron particles

Han,

Shi,

Hua

et al. 2024

SiO2 and Al2O3 micron particle effects on the mechanical and vibration properties of carbon fiber‐reinforced polymer (CFRP) composites were systematically investigated by incorporating these particles into the epoxy resin. CFRP laminates were prepared by adding various weight fractions (0–10 wt. %) of micron particles to the epoxy resin. The influence of cutout shape and the angle (θcf) between square cutout and fiber orientation on the vibrational performance of CFRP laminates were investigated. As the particle weight fraction (PWF) increased, the tensile, bending, interlaminar shear, and vibration properties of CFRP initially improved and then declined. The flexure strength of samples with 4 wt. % SiO2 and Al2O3 particles increased by 11.70%. The samples with 8 wt. % SiO2 and Al2O3 particles exhibited the highest damping ratio, which was 4.59 times greater than that of the samples without particles. The cutout shape and θcf influence the vibration performance of CFRP laminates. For the rectangular cutout, the sample with θcf = 22.5° exhibits the highest damping ratio, exceeding those at 0° and 45° by 2.28% and 7.10%, respectively.Highlights Three‐roll milling can disperse 4 wt.% particles in resin. SiO₂ and Al₂O₃ particles improve mechanical properties of CFRP. SiO2 and Al2O3 particles increased the damping ratio of CFRP by 359.22%. Circular cutout minimally reduces the first‐order natural frequency of CFRP. Angle between rectangular cutout and fiber affects CFRP vibrational properties.