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The present investigation focuses on developing cost-effective Carbon/Glass/Kevlar fiber-reinforced polymer hybrid composite laminates for achieving its synergistic effect on flexural and impact performance. It investigates the effect of stacking sequence induced by the use of different fiber types (Kevlar = K, glass = G, and carbon = C) on the flexural and impact performance of the composites. Five hybrid composites (labelled as A = [G2K3G2], B = [KG2CG2K], C = [CKGCGKC], D = [CGKCKGC], E = [CK2CK2C]) and three plain (i.e., non-hybrid) composites (F = [K]7, G = [G]7, H = [C]7) have been fabricated through manual pre-preg lay-up manufacturing techniques. The flexural strength and modulus, hardness, and Izod impact strength have been evaluated for the fabricated composites and compared. The results showed that the D-type hybrid composite achieves the maximum positive hybrid effect as compared to other hybrid composites, possesses a hardness of 59 BHN, a flexural strength of 380 MPa, and modulus of 36 GPa, and impact strength of 80 KJ/m2. The fracture surfaces of the hybrid composite specimen have been analysed using scanning electron microscopy, and compared against the properties achieved for enabling correlations. Furthermore, the cost-efficiency of the hybridization in terms of flexural strength/cost, modulus/cost, and impact strength/cost ratio were evaluated for potential engineering and design applications.

Glass fiber reinforced polymer composites (GFRPC) possess low strength in comparison to carbon fiber reinforced polymer composites (CFRPC). The degradation of the mechanical properties of seawater aged GFRPC is more than that of CFRPC. However, CFRPC is not commercially viable for all type of applications due to its high cost. Therefore, there is a need to hybridize carbon fiber with glass fiber to overcome the weakness of glass fiber reinforced polymer composites for marine application. In this investigation, there are five types of composites were considered, i.e., plain glass ([G]s), plain carbon ([C]s), [G3C2]S, [G2C2G]S and [GCG2C]S type of hybrid composites. The composites were seawater aged for 90 days. The results revealed that the tensile strength of seawater aged [GCG2C]S type hybrid composite was improved by 14% as compared to plain GFRPC. The flexural strength and modulus of seawater aged [GCG2C]S type hybrid composite were enhanced by 43% and 64% respectively in comparison to plain GFRPC. However, the impact strength of seawater aged [GCG2C]S type hybrid composites was reduced by 44.5% as compared to plain GFRPC. Furthermore, the structure-properties co-relationship was established from field emission scanning electron microscopy images.

Mechanical components are subjected to friction and wear necessitating evaluation of tribological properties of polymer based composites. The wear properties of composites depend on the material, operating conditions and on the stacking sequence in hybrid composites. In this article, evaluation of the mechanical properties and optimum parameters for minimum specific wear rate of the hybrid composite were determined. The Hybrid composite was fabricated by hand-layup method with stacking sequence [CG3C]S of glass and carbon fiber. The results revealed that the flexural strength and tensile strain are improved through hybridization. The wear properties of the hybrid composite was evaluated by DUCOM three body abrasion tester with different operating conditions such as applied load and sliding distance. Box–Behnken design of experiment was used to perform the experiments. Response Surface Methodology (RSM) was employed to model and optimize the parameters for minimum specific wear rate of hybrid composite. The predicted value for minimum specific wear rate of 16.8511×10-3mm3/Nm was applied load of 33N and sliding distance of 1221m for hybrid [CG3C]S which was in close agreement with experiment.

This paper focuses on establishing the limiting value of input heat flux for thermoelectric generators (TEG) under different environmental and operating conditions. The current study investigates the limiting input heat flux for TEG’s with allowable hot side temperature of 150.A fin block with 8 fin configuration and fin length of 60 mm is chosen as heat sink configuration for TEG. Computational Fluid Dynamics (CFD) model is developed and analyzed in this work after validation with published experimental results. CFD model consists of 4 TEGs encapsulated within a target block and a finned block, placed within a low speed wind tunnel. Forced laminar air flow in the wind tunnel up to 14 m/s simulates the outdoor wind conditions. Concentrated solar flux is applied to the face of the target block. Effect of ambient air temperature, fin material is studied. Angle of Attack (AOA) and wind direction which arises due to the 2 axis tacking of sun by Fresnel lens concentrator has also been studied and it is observed that maximum heat flux reaches 24,850 W/m2 for the TEG at 14 m/s wind speed, 24,000 W/m2 for 30Angle of Attack (AOA) under 5 m/s wind velocity. It is also observed that maximum heat flux varies by 147.77% with a change in wind velocity from 0 to 5 m/s, while the change is 11.43% when the change from 5 to 14 m/s.

Nano TiO2 particle is one of the promising inorganic nano fillers used in polymer matrix composites to enhance the mechanical properties. However, reliability of this type of nano composites is yet to be ensured in hydrothermal environment. The present work investigates the addition of nano TiO2 filler on water sorption, residual strength and thermal properties of glass fiber reinforced polymer (GFRP) composites. The results revealed that addition of 0.1 wt% TiO2 has reduced water diffusion coefficient by 9%, improved residual flexural strength by 19% and residual interlaminar shear strength by 18% among all the nano TiO2 modified composites. The improvement of mechanical properties in hydrothermal environment creates opportunity and reliability to be used in different engineering applications. Weibull design parameters are evaluated and found a good agreement between Weibull stress-strain curves and experimental one. Fractographic analysis confirmed the various failures and strengthening mechanisms of nano composites in dry and hydrothermal environment.

Fiber reinforced polymer composite is an important material for structural application. The diversified application of FRP composite has taken centre of attraction for interdisciplinary research. However, improvements on mechanical properties of this class of materials are still under research for different applications. In this paper we have modified the epoxy matrix by Al2O3, SiO2 and TiO2 micro particles in glass fiber/epoxy composite to improve the mechanical properties. The composites are fabricated by hand lay-up method. It is observed that mechanical properties like flexural strength, flexural modulus and ILSS are more in case of SiO2 modified epoxy composite compare to other micro modifiers. This may be because of smaller particle size of silica compare to others. Alumina modified epoxy composite increases the hardness and impact energy compare to other modifiers. Agglomeration of Al2O3 micro particles in the matrix is observed in SEM. This may be because of bigger particle size of Alumina. SEM analysis clearly indicates the mode of failure is the combination of crack in matrix, matrix/fiber debonding and fiber pull out for all types of composites.

The replacement of metallic components by carbon fiber reinforced polymer (CFRP) composites is inhibited due to expensive carbon fiber. This problem may be addressed through hybridization of carbon and glass fiber to reduce the cost and achieve desirable mechanical properties of the hybrid composites. In this article, the influence of stacking sequence of carbon and glass fiber on seawater diffusivity, tensile, flexural and impact strength of hybrid composites were evaluated. The composites were fabricated by hand layup technique and seawater aged for 90 days at room temperature. The results revealed that the flexural strength of [CG2CG]S type of hybrid composite was the highest, i.e. 490 MPa in dry condition. The seawater diffusivity of [CG2CG]S type hybrid composite was reduced by 44% as compared to that of plain glass fiber reinforced polymer composite. The retention of tensile, flexural and impact strength of seawater aged hybrid composite of [CG2CG]S type were about 95%, 82%, and 94% respectively. The failure modes of the hybrid composites in dry and seawater aged condition were observed by field emission scanning electron microscope (FE-SEM) to establish a possible structure properties co-relationship.

Polymer composites are sought for their enhanced properties and performance over conventional materials for diverse applications. Glass and carbon fibers are popularly used in polymer composites for their improved properties and lower weight. But carbon fiber being much stronger and costlier, the cost effectiveness of these composites can be ensured by optimal inclusion of carbon fiber in glass fiber composites to achieve requisite performance. This article examines the influence of stacking arrangement on mechanical properties of hybrid composite containing glass and carbon fiber of different strength and stiffness. Two hybrid composites of symmetrical pattern were fabricated; i.e. [GCGGC]S and [CGGCG]S having a fixed proportion of carbon fiber and glass fiber. Mechanical characterization was done by hardness, impact, tensile and flexural tests. It is found that hybrid composites with [GCGGC]S stacking sequence have tensile strength and flexural strength which are marginally more than [CGGCG]S. The [GCGGC]S lay-up has higher impact strength by 22.8%. However [CGGCG]S lay-up has higher hardness. The tensile modulus and flexural modulus of [CGGCG]s are higher by 20% and 36.2% respectively.