Effect of fiber orientation on mechanical properties of synthetic fiber reinforced hybrid composite: Experimental & computational analysis

Abstract

The hybrid composite received the momentum among the composite material scholars as well as researchers due to its unique features, aptitudes and applications in industrial fields. With regards to said rationales, this study fabricated a new carbon-glass-Kevlar fiber reinforced with epoxy resin (hybrid composite in research study) by executing the hand lay-up technique under different stacking sequences and fiber orientations (ply angles). Next, a few sample specimens of said hybrid composite were hacked for testing. Later, tensile strength, flexural strength, and hardness tests were performed by ASTM D638, ASTM D790, and ASTM D2583, respectively as well as FEM-Analysis for tensile and three point bending test also conducted with the help of Ansys. The results of both experimental and computational articulated that hybrid composite in research study) (1) Stacking orders enormously affects the tensile strength and flexural strength except hardness. (2) Fiber orientation influences the tensile and flexural strength except hardness. The discussed hybrid composite fabrication scheme, testing, data interpretation, FEM-Analysis and Experimental results are tabulated and represented graphically throughout the presented research work and the study concludes that the Stacking orders and Fiber orientation can alter the tensile and flexural properties with significant percentage.

Keywords

hybrid composite carbon fiber glass fiber Kevlar fiber mechanical properties FEM-analysis Ansys(ACP)

Introduction

In recent years, there has been a growing demand for lightweight, high-performance materials in industries such as automotive, aerospace, and defense. This demand has driven significant research into composite materials, which offer a unique combination of strength, stiffness, and reduced weight.¹ Among these, fiber-reinforced polymer (FRP) composites have gained prominence due to their ability to be tailored for specific applications by selecting appropriate reinforcing fibers and matrix materials. Traditionally, composites reinforced with synthetic fibers like carbon, glass, and Kevlar have been extensively used for their superior mechanical properties. However, with increasing interest in hybridization, combining multiple fibers into a single composite offers an opportunity to optimize material performance while balancing cost and sustainability.^2,3 Hybrid fiber-reinforced composites are composed of two or more types of fibers embedded in a polymer matrix, designed to leverage the strengths of each fiber. For instance, Kevlar fibers are renowned for their exceptional impact resistance and toughness, glass fibers provide cost-effective reinforcement with good tensile strength, and carbon fibers are known for their high stiffness and lightweight properties.^4,5 By combining these fibers in a hybrid composite, it is possible to create materials that outperform single-fiber composites in terms of strength, durability, and weight reduction. The use of hybrid fiber-reinforced polymer composites (HFRPCs) is especially attractive in the automotive industry, where reducing the weight of components like drive shafts, body panels, and structural members can significantly improve fuel efficiency and vehicle performance without compromising safety.^6,7 In this context, hybrid composites reinforced with Kevlar, glass, and carbon fibers can offer a unique combination of stiffness, strength, impact resistance, and fatigue performance making them ideal candidates for high-stress automotive applications. This research focuses on the mechanical characterization of hybrid reinforced polymer composites using Kevlar, glass, and carbon fibers, aiming to explore their mechanical properties and potential for automotive components.^8,9 Through finite element modeling (FEM), simulations, and experimental the study will examine critical parameters such as tensile strength, flexural strength, and hardness, providing insights into how different fiber combinations, orientation and stacking sequences affect the overall performance of the composite. This work will contribute to a deeper understanding of the benefits and trade-offs in hybrid fiber-reinforced composites and their potential for advanced engineering applications.¹⁰ R. Murugan et al.¹¹ investigated the epoxy-based woven fabric glass/carbon hybrid composite laminates. Where the static and dynamic mechanical properties were studied. The work also focused on the stacking sequence of the fibers. It was observed that the carbon laminate had maximum tensile strength and flexural strength whereas the glass laminate had minimum tensile strength and flexural strength but the impact strength found maximum for glass laminate and minimum for carbon laminate. For the hybrid composites, the tensile strength and impact strength of GCCG laminate was higher than the CGGC laminate but the flexural strength of GCCG laminate was lower than the CGGC laminate. C. L. Tan et al.¹² evaluated the mechanical performance of carbon and glass fiber reinforced hybrid composite. The method used for the fabrication of composite was vacuum-assisted resin transfer moulding (VARTM). VARTM is better than the hand layup method for producing high fiber volume fraction. The tensile strength and flexural strength of the hybridized composite were higher than the full glass fiber reinforcepolymer (FRP) composite. But a tensile and flexural strain of hybridized composite was lower than the full glass FRP composite. G. Agarwal et al.¹³ studied the effect of stacking sequence on the physical, mechanical and tribal properties of hybrid glass-carbon composites. They identified the best stack pattern (position and direction) is for GC4, i.e., where two to two layers of the carbon fabric was located at the end and remains. The tensile strength and hardness increase as the reinforcement of the fabric increases from 10 wt.% to 50 wt.% and flexural strength decreases as the increase. M. N. GuruRaja et al.¹⁴ investigated the tensile strength, tensile modulus, and peak load of glass/carbon hybrid composite. The orientation of fibre taken as 0^o, 30^o, 45^o, 60^o and 90^o. Experimental data shows that the ply angle at 0/90 has more tensile properties in comparison to other-oriented fibers. C. Dong et al.¹⁵ studied and investigated the glass and carbon fibre epoxy-based hybrid composite. The flexural properties were calculated experimentally and by using finite element analysis (FEM). Intra-ply configuration was taken for specimen preparation where glass fibre was added to the surface of carbon laminate. The hand layup technique was used for manufacturing specimens for testing. They concluded that with increasing percentage composition of glass fibre the flexural modulus decreases for both experimental analysis and finite element analysis. By substituting the carbon fibre with a thin layer of glass fibre the flexural strength increases and the highest flexural strength found in [0s-2/04T700S]. W. Zhou et al.¹⁶ studied the damage and failure behaviour of thick carbon/aramid hybrid composite. The orientation of fibres taken as 0^o, 45^o and 90^o. It was observed that the mechanical properties improved in the fibre direction. 90^o of carbon and 0^o of aramid fibre ensured maximum bending strength. 0^o of carbon and 90^o of aramid fiber ensured excellent toughness. Non-destructive testing technology was used for damage visualization and failure behaviour. V. Pandey et al.¹⁷ analyses the tensile strength, flexural behaviour, and impact resistance of Kevlar/carbon hybrid composite by computational simulation and concluded that the six layers of carbon fibre and six layers of Kevlar fibre ensured the high tensile stress and impact strength. Y. M. Kanitkar et al.¹⁸ calculated the flexural properties of the glass-Kevlar hybrid composite. The hand layup technique was taken for fabrication work. The three-point bending test carried out and concluded that the highest flexural strength shows in GKGKKGKG configuration and the maximum flexural modulus shows in CKGGKGGKG configuration. The objective of this study is to Fabrication of carbon-glass-Kevlar fiber reinforced epoxy-based hybrid composites in various configurations and determine the mechanical properties of hybrid carbon, glass, and Kevlar fiber composites, such as tensile, flexural strength, and hardness. To investigate the effects of fiber stacking order and orientation on the mechanical properties of hybrid composites. This study uniquely provides a systematic experimental–computational investigation of tri-fiber hybrid composites by simultaneously analyzing stacking sequence and fiber orientation effects, which has not been comprehensively reported in prior literature.

The objective of this study is to investigate the effect of fiber orientation on the mechanical properties of synthetic fiber reinforced hybrid composites through experimental testing and computational analysis. It aims to correlate the experimental results with simulation data to validate the material behavior. The study further seeks to determine the optimum fiber orientation that provides superior mechanical performance and structural efficiency.

Materials and methods

Materials

Fiber

Synthetic fibre has recently been used in a variety of applications, including the aircraft industries automobiles, and marine.¹⁹ The most used fibers are carbon, glass, and Kevlar fiber because of their excellent mechanical properties. Glass fiber is lightweight, strong, high heat resistance and less brittle. Carbon fiber has high rigidity, high tensile strength, and low thermal expansion very popular in aerospace civil engineering, military, and motorsports. Kevlar49 fiber has high tensile strength, lightweight, high toughness, and heat resistance Kevlar fiber has many applications, combustion protection material, bicycle tires and racing sails to bulletproof sweaters.²⁰ Due to some advantages over other fibers as mentioned above, the carbon, glass and Kevlar49 fiber chosen as the reinforcement materials for the project work. Table 1 shows properties of fibers. Carbon and glass fiber fabric supplied by Vihan Techno Trade, Gujarat, India. Kevlar49 fiber fabric supplied by Sree-ji Industries Gujarat, India.

Table 1.

Mechanical properties of fibers.

Properties	Carbon fiber	Glass fiber	Kevlar fiber
Thickness (mm)	0.129	0.168	0.25
Areal density (GSM)	235	430	160
Tensile strength (MPa)	4000	2500	3200

Epoxy resin and hardener

The epoxy resins extensively used for advanced composites due to their many advantages such as excellent adhesion to a wide variety of fibers, good performance at higher temperatures and greater mechanical and electrical properties.²¹ In calculation, they have small shrinkage in curing and good chemical resistance. It has numerous advantages, so epoxy resin (LY556) and hardener (HY951) selected as a matrix material. It is supplied by Herenba Instruments and Engineers, Chennai, India.

Fabrication of hybrid composite

The simplest method is the hand lay-up technique. In the hand lay-up technique, different layers are overlapping over the other layer. The carbon, glass and Kevlar49 fiber used as reinforcement and epoxy taken as a matrix material. The weight percentage of epoxy resin and hardener mixed in a ratio of 10:1. The gel coat applied to easily open the mould. The first layer of fibre placed over the gel coat and then matrix material is applied above the fibre layer and so on. The layers compressed in plain steel plate with the help of nut and bolt. The cast ofeach composite is cured for 25 h in room temperature. Hybrid composites of carbon, glass and Kevlar49 fibre arranged in different stacking sequence and orientations. Table 2 shows the stacking sequence and orientation of fiber. With the same fiber orientation, samples S1 and S2 have different stacking sequences, but samples S3 and S4 have the same stacking sequence with different fiber orientation (only for glass fiber). In sample S5 fiber running in 0^o for carbon and glass fiber with 0^o, 90^o Kevlar fiber. All three fibers in sample S6 are running at 45^o. Figure 1 fabricated hybrid composite plate respectively.²²

Table 2.

Stacking sequence and fiber orientation of hybrid composite.

S.No.	Samplecode	Stacking sequence	Orientation of fiber (ply angles)
1.	S1	KGCCGK	0^o, 90^o/45^o/60^o/−60^o/−45^o/0^o,90^o
2.	S2	CKGCKG	60^o/0^o, 90^o/45^o/−60^o/0^o, 90^o/−45^o
3.	S3	KCGGCK	0^o, 90^o/30^o/45^o/−45^o/-30^o/0^o,90^o
4.	S4	KCGGCK	0^o, 90^o/30^o/60^o/−60^o/-30^o/0^o,90^o
5.	S5	CKGGKC	0^o/0^o, 90^o/0^o/0^o/0^o, 90^o/0^o
6.	S6	GKCKKCKG	45^o/45^o, 45^o/45^o/45^o, 45^o/45^o, 45^o/45^o/45^o, 45^o/45^o

C: Carbon fiber; G: Glass fiber; K: Kevlar fiber.

Figure 1.

Composite laminates, carbon(C), glass(G), Kevlar(K) .

Design of hybrid composite in Ansys-(ACP)

Designing a hybrid composite in ANSYS-(ACP) first, defined the geometry of specimen (145 mm*12 mm) in ANSYS space claim design modular in Figure 2. Once the geometry is set up, create the composite layup, which involves defining the different layers, materials, orientations, and thicknesses that make up the hybrid composite (Figure 3). In ACP, define materials, as carbon fiber and glass fiber, and Kevlar fiber to create a hybrid specimen. After this all the samples that listed in Table 2 are made in Ansys-(ACP).

Figure 2.

Geometry of specimen.

Figure 3.

(a) Fiber orientation and layer directions (b) solid model of composite plate.

Characterization

Tensile test

The tensile test is usually carried out on flat materials. The tensile test was performed on a Universal Testing Machine (UTM) and the ASTM D638 standard. The dimension of the testing specimen is 145 mm × 12 mm. The image of the specimen during tensile testing. To conduct tensile test in Ansys boundary conditions are applied (fixing one end of the specimen while applying a displacement at the opposite end to simulate the tensile load) (Figure 4). A fine mesh is generated to ensure accurate stress and strain distribution results across the specimen.²³

Figure 4.

Tensile test setup in Ansys mechanical.

Flexural/3 point bending test

The purpose of a flexural test is to determine a material’s ability to handle bending it before breaks. The flexural test was carried out on the Universal Testing Machine (UTM) using ASTM D790 as a guideline. The dimension of testing specimen is 145 mm × 12 mm. The image of a specimen during flexural testing. To evaluate the flexural strength and behavior of the material, a finite element analysis (FEA) was performed using ANSYS software. The simulation setup involved applying boundary conditions to simulate a three-point bending test. The supports were modeled as fixed, and a displacement-controlled load was applied at the mid-span of the specimen and the analysis was conducted using a static structural module in Figure 5. The maximum stress at failure was recorded to determine the flexural strength.²⁴

Figure 5.

Three point bending test setup in Ansys mechanical.

Hardness

For hardness testing, a Barcol Hardness Tester (Barcol 934-1 durometer) was used. The ASTM D2583 standard was used. The Barcol Hardness Tester machine. For each stacking sequence and fiber-orientation configuration, three identical specimens were tested for tensile, flexural, and hardness measurements to ensure repeatability. The mean, standard deviation, and coefficient of variation were calculated to quantify specimen-to-specimen variation.

Result and discussion

The tensile strength, flexural strength, and hardness of the hybrid composite were all tested, and the results were compiled. The experimental and computational results of hybrid composite are shown in Table 4.1 and 4.2. Tested hybrid composite specimens are shown in Figure 4.1. The percentage error between experimental and FEM results ranged from approximately 1–3% for tensile and flexural strength across all configurations, confirming strong model–experiment agreement.

Tensile strength

The Experimental stress versus strain curves for hybrid composites S1, S2, S3, S4, S5, and S6 obtained from material testing (tensile test) using the said standard is shown below in Table 3. Hybrid composite S1 and S2 have different stacking sequences but the same orientation, whereas samples S3 and S4 have the same stacking sequence but different orientations. Furthermore, the average percentage deviation between experimental and FEM results was calculated to quantitatively evaluate the predictive accuracy of the computational model. The average deviation was found to be approximately 1.63% for tensile strength and 1.06% for flexural strength across all hybrid composite configurations. These low deviation values indicate excellent agreement between experimental observations and numerical simulations, thereby validating the reliability and accuracy of the developed FEM model for predicting the mechanical behavior of hybrid composites.

Table 3.

The tensile, flexural strength and hardness of hybrid composite.

Sample	Tensile strength (MPa)			Flexural strength (MPa)			Hardness
Sample	Experimental	Simulation	Deviation (%)	Experimental	Simulation	Deviation (%)	Hardness
S1	64.5	66.6	3.26	43.1	43.4	0.70	47.2
S2	174	176.8	1.61	39.7	39.5	0.50	39
S3	84.4	85.30	1.07	114	118	3.50	19.4
S4	88.5	88.6	0.11	98.5	98.1	0.41	19.2
S5	183	184.06	0.58	573	566.5	1.13	40.6
S6	50.3	51.9	3.18	58.7	58.78	0.14	44.4

It is found that stacking sequence and orientation of fiber both affect the tensile modulus. Altering the stacking sequence from S1 (KGCCGK) to S2 (CKGCKG), the tensile strength increases by 62.93% and tensile modulus increases by 27.17% because of carbon and glass fiber in the outer layer (Table 4). On the other hand, the fiber orientation of glass fiber from S3 (45/−45) to S4 (60/−60), the tensile strength and modulus increases by 4.63% and 71.79% respectively found from experimental and computational tensile test. Carbon fiber in the outer layer has a higher tensile strength than carbon fiber in the inner layer. The S5 hybrid composite has a 0°-fiber orientation and the highest tensile strength (183 MPa) as compared to all the hybrid composites studied in present research. The superior tensile performance of S5 can be attributed to its optimized stacking sequence (CKGGKC), where high-strength carbon fibers are positioned near the outer layers, allowing them to effectively carry the maximum tensile load. Additionally, the predominance of 0° fiber orientation ensures that the applied load is aligned with the fiber direction, resulting in efficient stress transfer and minimized matrix-dominated deformation. The hybrid combination of carbon, glass, and Kevlar fibers further contributes to improved load distribution and delayed failure, leading to enhanced tensile strength. The hybrid composite S6 have 45^o fiber orientation for all the fibers. The results obtained from the tensile testing indicate that sample S5 attained the highest tensile strength of 183 MPa (experimental). The fracture patterns observed during testing indicate that failure was dominated by fiber rupture in S5 and by shear distortion and delamination in S6, consistent with their respective ply orientations. The illustrating enhanced load-bearing capability attributable to its stacking sequence (CKGGKC) and fiber orientation at 0°/0°, 90°/0°/0°, and 90°/0°, which facilitated effective stress transmission along the fiber axis, as depicted in the stress versus strain diagram illustrated in Figure 6. Conversely, sample S6 exhibited the lowest tensile strength of 50.3 MPa, primarily due to its fibers being oriented at 45°, which diminished alignment with the tensile load and precipitated premature failure. In ±45°-dominated laminates such as S6, the applied tensile load cannot be transferred efficiently along the fiber axis because the fibers are oriented away from the loading direction. Instead of direct axial stress transfer, the laminate experiences significant in-plane shear stresses within the matrix and at the fiber–matrix interface. This shear-dominated deformation reduces the effective contribution of high-strength fibers, promotes interlaminar delamination, and accelerates premature failure. Additionally, the absence of sufficient 0° fiber reinforcement limits axial stiffness and load-bearing capability, resulting in the comparatively lower tensile strength observed for S6. The other samples (S1–S4) demonstrated moderate tensile characteristics, suggesting that the interplay of mixed orientations and hybrid stacking significantly impacts stress distribution and the failure mechanisms. The simulation outcomes were in close alignment with the experimental results, thereby affirming the validity of the computational model as shown in Figure 7.

Table 4.

Tensile and flexural modulus of hybrid composite.

Hybrid composite	Tensile modulus (MPa)	Flexural modulus (MPa)
S1	1260	738
S2	1730	1340
S3	1120	5440
S4	3970	4160
S5	3170	9050
S6	1070	3110

Figure 6.

Tensile strength comparison for all hybrid composite samples.

Figure 7.

Tensile test results for hybrid composite.

The significant variation in tensile modulus observed among different stacking configurations is primarily attributed to fiber orientation and the effective contribution of high-stiffness fibers (Table 4). Specimens such as S4 and S5 exhibit higher tensile modulus due to the presence of a greater proportion of 0°-aligned fibers, which facilitate efficient load transfer along the fiber direction and enhance axial stiffness. In contrast, specimen S6, with fibers predominantly oriented at 45°, demonstrates the lowest tensile modulus (1070 MPa), as off-axis fiber orientations promote shear deformation and reduce effective stiffness. Furthermore, the contribution of carbon fibers being the stiffest among the reinforcements is maximized when aligned with the loading direction and properly distributed within the stacking sequence. Therefore, both fiber orientation and stacking play a crucial role in governing the overall tensile modulus of hybrid composites. The relatively higher flexural modulus of S5 can be attributed to the favorable stress distribution across the laminate thickness, where stiff carbon and glass fibers are positioned near the outer layers. During bending, maximum tensile and compressive stresses are experienced at the outer surfaces, allowing these high-modulus fibers to effectively resist deformation and enhance overall stiffness.

Flexural strength

Below is the stress versus strain curves (Figure 8) for hybrid composites S1, S2, S3, S4, S5, and S6 obtained from material testing (flexural test) using the said standard. The flexural strength and modulus is found to be affected by both the stacking sequence and the fiber orientation. Changing the stacking sequence from S1 (KGCCGK) to S2 (CKGCKG) tensile strength decreases by 7.89%, but flexural modulus increases by 44.93% (Table 4). The fiber orientation of glass fiber from S3 (45/−45) to S4 (60/−60), the flexural strength and modulus decrease by 13.60% and 23.53% respectively. It is because of flexural strength decreases with increase in fiber angle from 0^o to 90^o.The hybrid composite shows better flexural strength on 0^o fiber orientation as compared to 90^o fiber orientation. If carbon fiber is in outer layer, then flexural strength is more as compared to inner layer. The hybrid composite S5 have 0^o fiber orientation and it have highest flexural strength (573 MPa) and modulus (9050 MPa) among all hybrid composite presents in this study. For comparison, the stress versus strain curve obtained from the flexural test of the hybrid composite is shown in a single graph. In the examination of flexural properties, specimen S5 consistently demonstrated the highest recorded flexural strength (573 MPa as per experimental analysis), underscoring its remarkable resistance to bending attributed to the predominance of 0° and 90° fiber orientations, which conferred substantial stiffness under flexural stress. The enhanced flexural performance of S5 is primarily due to the placement of stiff carbon and glass fibers in the outer layers of the laminate, where maximum bending stresses occur during flexural loading. This outer layer dominance significantly increases resistance to bending. Furthermore, the dominant 0° fiber orientation improves longitudinal stiffness and reduces shear deformation, while Kevlar fibers contribute to improved toughness and resistance to crack propagation. Specimens S3 and S4 also revealed commendable flexural strength metrics (114 MPa and 98.5 MPa, respectively) as a result of an optimal amalgamation of carbon and glass fibers that enhanced the capacity to bear loads during bending. The early cracking seen in S1 and S2 suggests that interlaminar stresses-initiated failure before fiber breakage, explaining their lower flexural strength. Conversely, specimens S1 and S2 exhibited diminished flexural strength values, potentially due to suboptimal fiber orientation and insufficient interlaminar adhesion. The outcomes of the simulations exhibited a strong correlation with the experimental findings, thereby substantiating the predictive accuracy regarding the structural performance of the composite (Figure 9).

Figure 8.

Experimental flexural strength comparison for all hybrid composite samples.

Figure 9.

Three point bending test results for hybrid composite.

Hardness

Figure 10 shows the hardness of a hybrid composite. The hardness is primarily affected by the stacking sequence and surface fiber distribution, while fiber orientation shows a comparatively smaller influence. The hardness decreases by 17.37% when the stacking sequence is changed from S1 (KGCCGK) to S2 (CKGCKG). The fiber orientation of glass fiber from S3 (45/−45) to S4 (60/−60), the hardness decreases by only 1% and it is not considered because of small changes. These results suggest that the stacking sequence and fiber type distribution significantly influence the surface hardness and wear resistance of the hybrid composite. Although hardness was found to be less sensitive to fiber orientation compared to tensile and flexural properties, the observed hardness variation (19.2–47.2) indicates the influence of secondary stacking effects and surface fiber distribution. The hardness test primarily measures localized surface resistance to indentation; therefore, the type of fiber present near the outer laminate surface plays an important role. Specimens containing carbon-rich outer layers exhibited relatively higher hardness due to the inherently higher stiffness of carbon fibers, whereas configurations with greater Kevlar exposure or off-axis fiber orientations showed comparatively lower hardness values. In addition, interfacial bonding and local resin distribution within different stacking sequences may also contribute to variations in indentation resistance. The hardness of hybrid composite in decreasing order is:

Figure 10.

Hardness value of hybrid composite.

Statistical analysis of testing results

A comprehensive statistical analysis was conducted to evaluate the consistency and reliability of the experimental outcomes obtained for the hybrid composite specimens. Each mechanical characterization was executed on three identical specimens for every stacking sequence and fiber orientation configuration. This methodology ensured that the results accurately reflected both the intrinsic mechanical properties of the material and the reproducibility of the experimental protocol. The mean value, standard deviation (SD), and coefficient of variation (CV) were computed for each test group to assess the statistical dispersion and variability within the recorded data. Table 5 presents a summary of the statistical parameters associated with the tensile strength findings of all six hybrid composite samples.

Table 5.

Statistical analysis of tensile strength results for hybrid composite specimens.

Sample	Mean tensile strength (MPa)	Standard deviation (SD)	Coefficient of variation (CV, %)
S1	64.5	0.89	1.38
S2	174.1	1.39	0.80
S3	84.43	1.07	1.27
S4	88.47	0.59	0.67
S5	183.0	0.46	0.25
S6	50.33	0.38	0.76

The statistical analysis reveals that both the standard deviation and the coefficient of variation values are markedly low across all specimens, thereby affirming exceptional experimental repeatability and measurement accuracy. Among the various configurations examined, the S5 specimen demonstrated the highest mean tensile strength (183 MPa) while concurrently exhibiting the lowest coefficient of variation (0.25%), which indicates remarkable consistency and stability in load-bearing performance. In contrast, the S6 configuration, which featured fibers oriented at 45° for all reinforcements, displayed a relatively lower tensile strength but preserved a high level of experimental consistency, as evidenced by a coefficient of variation below 1%. The minimal variation observed across all samples substantiates that the hand lay-up fabrication technique yielded homogenous specimens and that the testing conditions were meticulously regulated. This consistency serves to enhance the credibility of the experimental outcomes and corroborates their association with the results derived from finite element analysis. In addition, an analogous statistical approach was employed for the flexural and hardness test results, which similarly demonstrated equivalent levels of repeatability and precision. In summary, the incorporation of statistical metrics bolsters the dependability of the experimental findings and substantiates the identified impact of stacking sequence and fiber orientation on the mechanical properties of hybrid composites.

Conclusion

Changes in stacking sequence and fibre orientation were used to investigate the variation in mechanical properties of a carbon-glass-Kevlar fiber epoxy-based hybrid composite using experimental and computational methods. After conducting simulation and experimental tests on different samples it is possible to conclude the following:

(1) The stacking sequence affects the tensile, flexural strength and hardness.

(2) The fiber orientation affects the tensile strength and flexural strength but does not affect hardness.

(3) The tensile and flexural modulus affected by both stacking sequence and fiber orientation. The tensile modulus is maximum for S4 (3970 MPa) and minimum for S6 (1070 MPa) whereas flexural modulus is maximum for S5 (9050 MPa) and minimum for S1 (738 MPa).

(4) The maximum tensile strength found for S5 is 183 MPa, and the minimum for S6 is 50.3 MPa.

(5) The maximum flexural strength found for S5 is 573 MPa, and the minimum for S1 is 39.7 MPa.

(6) The maximum hardness found for S1 is 47.2, and the minimum for S4 is 19.2.

(7) The simulation results closely matched the experimental data, confirming the accuracy and reliability of the computational model in predicting the mechanical behavior of the hybrid composites.

Footnotes

ORCID iD

Yugendra Kumar Sahu

Author contributions

Yugendra Kumar Sahu and Chandan were responsible for the data collection, specimen fabrication, and experimental testing. Sidhant Dubey carried out the simulation and finite element analysis. The overall supervision, guidance, and technical review of the work were provided by T. V. Arjunan. All authors discussed the results, contributed to the interpretation of data, and approved the final version of the manuscript.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

References

Ebrahimnezhad-Khaljiri

Eslami-Farsani

Akbarzadeh

. Effect of interlayer hybridization of carbon, kevlar, and glass fibers with oxidized polyacrylonitrile fibers on the mechanical behaviors of hybrid composites. Proc Inst Mech Eng Part C J Mech Eng Sci 2020; 234(9): 1823–1835. https://doi.org/10.1177/0954406219897935

Gupta

Shohel

Singh

, et al. Study on mechanical properties of natural fiber (Jute)/synthetic fiber (glass) reinforced polymer hybrid composite by representative volume element using finite element analysis: a numerical approach and validated by experiment. Hybrid Adv 2024; 6: 100239. https://doi.org/10.1016/j.hybadv.2024.100239

Nabeel

Nasir

Sattar

, et al. Numerical and experimental evaluation of the mechanical behavior of kevlar/glass fiber reinforced epoxy hybrid composites. J Mech Sci Technol 2020; 34(11): 4613–4619. https://doi.org/10.1007/s12206-020-1019-1

Gangwar

Kumar

Yaylaci

, et al. Computational modelling and mechanical characteristics of polymeric hybrid composite materials: an extensive review. Arch Comput Methods Eng 2024; 31(7): 3901–3921.

Rout

Nayak

Patnaik

, et al. Development of improved flexural and impact performance of kevlar/carbon/glass fibers reinforced polymer hybrid composites. J Compos Sci 2022; 6(9): 245. https://doi.org/10.3390/jcs6090245

Ishtiaq

Saleem

Naveed

, et al. Glass–carbon–kevlar fiber reinforced hybrid polymer composite (HPC): part (A) mechanical and thermal characterization for high GSM laminates. Compos Part C Open Access 2024; 14: 100468. https://doi.org/10.1016/j.jcomc.2024.100468

Sahu

Arjunan

Singh

, et al. Stimuli-responsive nanofiller-based shape memory polymer composites: actuation methods and biomedical applications. J Thermoplast Compos Mater 2025; 39: 2050–2115. https://doi.org/10.1177/08927057251377054

Mohapatra

Deo

Mishra

, et al. Mechanical characterization of kenaf/glass fibre hybrid composite laminates: an experimental and numerical approach. Proc Inst Mech Eng Part E J Process Mech Eng 2023; 237(6): 2440–2448. https://doi.org/10.1177/09544089221136813

Vinay

Govindaraju

Banakar

. A review on investigation on the influence of reinforcement on mechanical properties of hybrid composites. Int J Pure Appl Sci Technol 2014; 24(2): 39–46.

10.

Sahu

Arjunan

Singh

, et al. Investigation of shape memory and mechanical properties of MWCNT and graphene nano filler reinforced epoxy composite. J Polym Res 2025; 32(9): 298. https://doi.org/10.1007/s10965-025-04507-9

11.

Murugan

Ramesh

Padmanabhan

. Investigation on static and dynamic mechanical properties of epoxy based woven fabric glass/carbon hybrid composite laminates. Procedia Eng 2014; 97: 459–468. https://doi.org/10.1016/j.proeng.2014.12.270

12.

Tan

Azmi

Muhammad

. Delamination and surface roughness analyses in drilling hybrid carbon/glass composite. Mater Manuf Process 2016; 31(10): 1366–1376. https://doi.org/10.1080/10426914.2015.1103864

13.

Agarwal

Patnaik

Sharma

, et al. Effect of stacking sequence on physical, mechanical and tribological properties of glass-carbon hybrid composites. Friction 2014; 2: 354–364. https://doi.org/10.1007/s40544-014-0068-9

14.

GuruRaja

HariRao

. Hybrid effects on tensile properties of carbon/glass angle ply composites. Adv Mater 2013; 12(2): 36–41.

15.

Dong

. Effects of process-induced voids on the properties of fibre reinforced composites. J Mater Sci Technol 2016; 32(7): 597–604. https://doi.org/10.1016/j.jmst.2016.04.011

16.

Zhou

Zhang

Ding

, et al. Fabrication and tribological properties of carbon nanotubes reinforced Al composites prepared by pressureless infiltration technique. Compos Part A Appl Sci Manuf 2007; 38(2): 301–306. https://doi.org/10.1016/j.compositesa.2006.04.004

17.

Pandey

Ahn

Lee

, et al. Recent advances in the application of natural fiber based composites. Macromol Mater Eng 2010; 295(11): 975–989. https://doi.org/10.1002/mame.201000095

18.

Kanitkar

Kulkarni

Wangikar

. Investigation of flexural properties of glass-kevlar hybrid composite. Eur J Eng Technol Res 2016; 1(1): 25–29. https://doi.org/10.24018/ejeng.2016.1.1.90

19.

Rajesh

Ramnath

Elanchezhian

, et al. Investigation of tensile behavior of kevlar composite. Mater Today Proc 2018; 5: 1156–1161.

20.

Bandaru

Chouhan

Bhatnagar

. High strain rate compression testing of intra-ply and inter-ply hybrid thermoplastic composites reinforced with kevlar/basalt fibers. Polym Test 2020; 84: 106407. https://doi.org/10.1016/j.polymertesting.2020.106407

21.

Sahu

Arjunan

Singh

, et al. Post-curing effect on tribological properties of MWCNTs-B4C and Graphene-B4C polymer epoxy composites. High Perform Polym 2026; 0: 09540083261422657.

22.

Ismail

Rejab

MRM

Siregar

, et al. Mechanical properties of hybrid glass fiber/rice husk reinforced polymer composite. Mater Today Proc 2020; 27: 1749–1755. https://doi.org/10.1016/j.matpr.2020.03.660

23.

Larsen

Andersen

Thorning

, et al. Comparison of friction and wear for an epoxy resin reinforced by a glass or a carbon/aramid hybrid weave. Wear 2007; 262: 1013–1020. https://doi.org/10.1016/j.wear.2006.10.004

24.

Sahu

Arjunan

Singh

, et al. Thermomechanical, tribological, and shape memory analysis of dual dispersion of MWCNT-B₄C and Graphene-B₄C composites: a comparative study. J Mater Eng Perform 2026. https://doi.org/10.1007/s11665-026-13745-x