Advanced sustainable bio-composites: Integrating continuous fiber reinforcement with biomimetic design for high-performance applications

Abstract

The growing need for eco-friendly materials has driven efforts to create new bio-composites that reduce reliance on non-renewable resources and minimize environmental damage. However, bio-composites often need more strength and durability than traditional petroleum-based materials, making them unsuitable for demanding engineering applications. This study addresses these challenges by adding continuous fibers to a bio-based matrix, significantly improving the material’s strength, stiffness, and lifespan. The enhanced composites reached a maximum tensile strength of 120 MPa, averaging 105 MPa, while their flexural strength averaged 90 MPa. Continuous fibers provide the structural support needed to handle heavy loads and resist bending under stress. Additionally, this research uses biomimetic design—drawing inspiration from natural structures—to optimize the composite’s internal structure. By mimicking how natural materials are organized at the microscopic level, the composites achieve a better balance of density, toughness, and stiffness, along with improved resistance to damage. The findings show that combining continuous fibers with biomimetic design in GO/AG nanocomposites creates high-performing, eco-friendly materials without relying on synthetic polymers. These advancements pave the way for sustainable materials suitable for automotive, aerospace, and construction industries.

Introduction

With growing environmental concerns and the depletion of raw material resources, eco-friendly materials have gained importance. Bio-based composites have emerged as a sustainable alternative to synthetic materials because they are recyclable and have a lower environmental impact. These composites, made from plant fibers and bio-polymers, are biodegradable and help reduce the carbon footprint. ¹ According to the European Bioplastics Association, the production of bio-based composites reached 2.11 million tonnes in 2020, driven by the increasing demand for green products. However, these materials have lower tensile strength, stiffness, and impact resistance than synthetic composites, limiting their use in demanding fields like automotive, aerospace, and construction. ² The term “Advanced Sustainable” refers to the integration of innovative technologies and methodologies aimed at enhancing the performance, durability, and applicability of materials while ensuring environmental responsibility. It combines cutting-edge design principles with sustainable practices to develop solutions that meet both high-performance industrial requirements and global ecological objectives.

Improving the mechanical properties of bio-based composites is challenging due to weak bonding between the fibers and the matrix. While natural fibers are sustainable, they are less robust than carbon or glass fibers, making the composites less durable and more prone to degradation. Additionally, natural fibers absorb moisture due to their hydrophilic nature, weakening their bonding with the matrix and reducing the overall mechanical strength.^3,4 Existing design methods for improving the microstructure and mechanical properties of bio-based composites remain inadequate for high-performance applications. ⁵

This study addresses these challenges by incorporating continuous fiber reinforcement and biomimetic design principles into bio-based composites. Continuous fibers improve the tensile strength and stiffness of the composites, while biomimetic designs mimic natural hierarchical systems to optimize the microstructure for better performance and eco-efficiency.^6,7 This approach aims to make bio-based composites perform as well as or better than synthetic materials while being more sustainable.

Synthetic materials, though widely used, are not environmentally sustainable. Biodegradable composites from renewable resources can reduce energy use and environmental impact during production. However, bio-based composites lack the necessary mechanical strength for complex automotive, aerospace, and construction engineering applications. This research aims to bridge the performance gap between bio-based and synthetic composites by enhancing their strength and durability through continuous fiber reinforcement and biomimetic design. ⁸

Comparative analysis of prior research

Several studies have explored the development and application of bio-based and biomimetic materials. Bezerra and Del Mastro ⁹ studied the use of babassu fibers in geotextiles, highlighting their environmental benefits and mechanical performance, though their applications remain limited to geotextiles. Similarly, Ahmad et al. ¹ reviewed natural fiber composites (NFCs) used in construction, finding that while they reduce carbon emissions, they still lag behind synthetic alternatives in mechanical properties.

Libonati et al. ¹⁰ designed a biomimetic composite inspired by human bone, achieving improved toughness and strength, but the complex design limited its manufacturability. Fu et al. ¹¹ developed biomimetic laminated boards using starch and maize stalk fibers, demonstrating good flexibility but encountering scalability challenges. Araújo and José ¹² experimented with bio-based materials like Agave Sisalana to create lightweight and stiff composites using biomimetic methods, but their industrial applications remain constrained.

Other studies, such as those by Krishnan et al. ¹³ and Malekmohammadi et al., ¹⁴ explored biomimetic principles for wind energy systems and biomedical applications, respectively, but faced issues with material performance and stability. Additionally, Nguyen et al. ¹⁵ explored mycelium-based natural fiber composites, both of which showed promise but suffered from inconsistent properties.

Boaretto et al. ¹⁶ examined biomimetic designs for more efficient mobility systems, identifying integration challenges in existing technologies. Similarly, Broeckhoven et al. ¹⁷ reviewed biomimetic designs in additive manufacturing, emphasizing their aesthetic and functional benefits but highlighting the difficulty of replicating complex structures.

Uchiyama et al. ¹⁸ explored biomimetics in architecture and urban design, highlighting sustainability opportunities. However, existing biomimetic adhesive solutions remain unsuitable for all climate zones. Zhang and Le Ferrand ¹⁹ studied bio-sourced clay composites but found that their long-term performance remains unclear. Lastly, Envelopes et al. ²⁰ focused on biological building envelopes, identifying the need for advancements in material science to overcome existing limitations.^21–24 Table 1 shows the Comparative Analysis of the previous study.

Table 1.

Comparative analysis of previous study.

Reference	Technique	Results	Limitations	Findings
3	Use of babassu fibers in geotextiles	Improved mechanical properties and environmental benefits	Limited to specific applications in geotextiles	Babassu fibers have the potential for sustainable material development
4	Review of biomimetic and composite materials for mobility	Reduced weight and improved fuel efficiency	Integration challenges in existing systems	Biomimetic composites offer significant efficiency gains in mobility applications.
6	Biomimetic experimentation with Agave sisalana	High lightness and resistance in composites	Limited applications and need for further research	Promising results in light and bio-based solid materials
9	Laminated boards from starch and maize stalk fiber	Good flexural properties	Challenges in scaling up production	Potential for sustainable composite materials, though with scalability issues
13	Biomimetic design inspired by human bone	Enhanced toughness and strength of composites	Complex design process, not easily scalable	Biomimetic principles can significantly improve composite performance
15	Biomimetic fiber-reinforced compound materials	Structural efficiency improved	Difficult to replicate natural structures at scale	Biomimetic approaches offer structural advantages in composites
17	Mycelium-based natural fiber-reinforced composites	Demonstrated good mechanical properties	Variability in material properties	Mycelium composites are viable but need standardization

Natural fiber composites generally have lower tensile strength, stiffness, and impact resistance than synthetic composites due to the variability of natural fibers and poor bonding at the fiber-matrix interface. ⁷ Their moisture-absorbing nature further weakens their properties. Traditional design methods must address these limitations effectively, especially for applications requiring rugged and resilient materials. Therefore, advanced techniques, such as high-volume reinforcement and biomimetic design patterns, are essential for improving bio-based composites. ⁸

The traditional methods for designing high-strength composites do not focus on optimizing microstructural elements, leading to less efficient materials. Research shows that the microstructure significantly influences the mechanical properties of composites. By optimizing parameters like fiber orientation and matrix distribution, it is possible to create composites with low compliance, high stiffness, and enhanced durability. These improvements make bio-based composites suitable for high-performance automotive, aerospace, and construction applications. This study demonstrates that bio-based composites can achieve the strength and durability of synthetic materials through optimized microstructures, thereby advancing their industrial and environmental appeal. This research aims to improve the mechanical properties of bio-based composites by using continuous fiber reinforcement and biomimetic design. The specific objectives of this study are:

a. Develop a mathematical model to establish a clear relationship between the mechanical properties of bio-based composites and their microstructure.

b. Use biomimetic design principles to improve the microstructure, focusing on increasing tensile strength, stiffness, and interfacial shear strength while maintaining low compliance.

c. Investigate how continuous fibers enhance the load-bearing capacity and durability of bio-based composites.

d. Conduct experiments and simulations to validate the proposed optimization framework and ensure the methods are effective and reliable.

e. Advance the development of high-performance, eco-friendly composites suitable for automotive, aerospace, and construction industries.

f. This study is unique because it combines continuous fiber reinforcement with biomimetic design, mimicking natural structures to create optimized microstructures. Unlike traditional approaches, this research focuses on achieving high mechanical performance and environmental sustainability, bridging the gap between bio-based and synthetic composites for high-performance engineering applications.

Methodology

The methodology for developing the biomimetic bio-based composite model encompasses several vital components, beginning with the inputs, which include a biodegradable polymer matrix, continuous fibers such as carbon, glass, or natural fibers like jute and flax, and design inspiration derived from biomimetic structures such as bone and nacre. The process involves multiple stages: fiber preparation and alignment, matrix preparation with careful control of mixing and viscosity, fiber integration using methods like vacuum infusion and filament winding, and finally, the curing process where heat or pressure solidifies the matrix to form the composite. The outputs of this process are high-performance reinforced composites with enhanced mechanical properties, including tensile strength, stiffness, and interfacial shear strength. Additional outputs include simulated stress distribution results, such as Von Mises stress and tensile strength, fire resistance, vibration damping, and sustainability metrics. Feedback loops are integrated into the methodology to ensure continuous improvement. Simulation results are used to optimize material design, while experimental validations refine and confirm simulation parameters, achieving a balanced and practical approach to composite development. ²⁵

Problem formulation

Bio-based composites face significant challenges due to their mechanical performance limitations, primarily caused by the low tensile strength of natural fibers and weak bonding between fibers and the matrix. These deficiencies restrict their use in high-performance applications such as the automotive and aerospace industries. To address these issues, this research focuses on improving bio-based composites’ tensile strength, stiffness, and interfacial shear strength by optimizing their material properties and microstructure.

The mechanical performance of the composite is modelled using three key parameters: tensile strength $\left(\sigma c\right)$ , stiffness $\left(Ec\right)$ , and interfacial shear strength $\left(\tau c\right)$ . These parameters depend on design variables such as fiber volume fraction, matrix properties, and the strength of fiber-matrix interactions. The tensile strength is calculated using the rule of mixtures, incorporating the fiber and matrix volume fractions, their respective strengths, and an efficiency factor for stress transfer. Similarly, stiffness depends on Young’s modulus of the fibers and matrix, with additional contributions from fiber-matrix interactions. The interfacial shear strength accounts for the intrinsic bonding strength between the fiber and matrix, adjusted for stress distribution. The objective is to maximize these mechanical properties through optimal material design, enabling bio-based composites to compete with synthetic alternatives.

In addition to material design, optimizing the microstructure of bio-based composites is crucial for enhancing their performance. This involves parameters like fiber orientation, aspect ratio, and matrix phase distribution. The microstructural performance is modelled by integrating fiber orientation and stress distribution with the matrix phase properties and compliance. Fiber orientation impacts how stresses are distributed within the composite, while the matrix phase distribution ensures uniform load transfer. The optimization goal is to maximize stress distribution efficiency and minimize compliance, resulting in a more robust and durable composite.

This research aims to enhance the mechanical performance of bio-based composites by combining improvements in material properties and microstructure. The ultimate objective is to develop eco-friendly composites that meet the high-performance demands of automotive, aerospace, and construction industries while maintaining their sustainable advantages over synthetic materials.

Experimental design

This study utilizes a research method based on a simulation where the mechanical performance of bio-based composites reinforced with continuous fibers and biomimetic design is analyzed using real-time simulations. The simulations were performed using sophisticated computational simulation techniques that exposed the structure and behavior of these composite materials under stress. This process evaluates the strength and stiffness of the materials and the ISF in laboratory conditions, not simultaneously. The simulation-based real-time study directly supports the study’s goal of improving the bio-based composite’s performance, as the real-world insights into their use contribute to academic research on the materials’ integration into high-strength engineering industries, including automotive, aerospace, and construction. The constituents utilized in the present work are bio-based polymer matrices and continuous fibers for reinforcement. The composite matrix is synthesized from plant-based, bio-based, and environmentally friendly material, as it degrades naturally. Continuous fibers like natural or synthetic fibers like glass or carbon fibers were integrated into the matrix to improve the mechanical characteristics of the composites. Tensile strength, stiffness properties, and matrix compatibility informed the choice of the continuous fibers incorporated in this research. Some of the equipment used in the study is a tensile testing machine of high accuracy for establishing the mechanical characteristics, Microscopy systems for analyzing the morphology of the composite Reinforcement structures, Computational analysis software such as ABAQUS and COMSOL for simulating the mechanical attributes of reinforced composite materials. Also, for further thermal analysis, techniques such as Differential Scanning Calorimetry (DSC) were used to study the thermal characteristics of the composites.

Experimental setup

Kroll and coworkers used this approach to assess the mechanical characteristics of continuous fiber-reinforced bio-based composites. Special measures were thus taken to create realistic stress conditions during experiments. The mechanical properties of the tensile samples were characterized by a computer-controlled high-precision tensile testing machine at different temperatures and relative humidity values. The electronic device was tested under normal conditions, with a room temperature of 25°C and relative humidity of 50%. The testing was conducted at room temperature, 25 centigrade, and relative humidity was 50%. In this study, the samples were loaded at a constant rate in the tensile machine, and the load at failure was recorded for each sample. To gather fiber orientation and matrix data and study the microstructure of the samples before and post-testing digital microscopes were used.

Besides practical tests, the performance of the composite structure was modeled and estimated using the COMSOL Multiphysics software. These tools enabled accurate modelling of stress distribution, tensile strength, and interface shear strength. The computer simulation results were verified by comparing them with the experimental values obtained. Table 2 shows the Summary of Experimental Setup.

Table 2.

Summary of experimental setup.

Parameter	Experimental condition/Equipment
Temperature	°C (room temperature)
Relative humidity	%
Tensile testing machine	High-precision tensile machine
Digital microscope	Observation of composite microstructure
Simulation tools	ABAQUS, COMSOL Multiphysics
Load application rate	Constant rate until failure
Mechanical properties measured	Tensile strength, stiffness, and interfacial shear strength

Fiber reinforcement process

Embedding the continuous fibers into the bio-based composite matrix is essential in improving the composite material’s mechanical characteristics. This process involves several methods and techniques, which are described below:

Continuous fibers, such as glass, carbon, or natural fibers (e.g., jute, flax), are sourced and prepared by cleaning, cutting, and aligning them according to the desired specifications. Longitudinal materials, including glass, carbon, or natural (e.g., jute, flax) fiber, are procured, end-cleaned, cut, and arranged according to application necessity. A biodegradable resin matrix (e.g., epoxy or polyester) is obtained, which may contain a filler to improve characteristics such as adhesion, flexibility, thermal stability, and others. Fibers are manually placed into a mold and saturated with the resin, allowing for control over fiber orientation. Continuous fibers are chopped and sprayed into a mold, where the resin is simultaneously applied. Continuous fibers are wound around a rotating mandrel to form a composite layer, ensuring uniform distribution of fibers and resin. Fibers are placed in a mold, and resin is drawn through the fibers using a vacuum, promoting complete saturation without air entrapment. Using heat and/or pressure, the resin is cured to increase the formation of its polymer network and subsequently fixes the fibers to the matrix.

These are fiber weight fraction, fiber volume fraction, fiber orientation angle, resin viscosity, curing temperature, and curing time, all of which strongly impact the composite’s mechanical properties. Table 3 shows the Parameters Involved in the Fiber Reinforcement Process.

Table 3.

Parameters involved in fiber reinforcement process.

Parameter	Description
Fiber content (%)	The weight percentage of fibers in the composite influences strength and stiffness.
Fiber orientation (°)	The fibers angles are relative to the load direction affecting load transfer efficiency.
Resin viscosity (Pa.s)	The resin’s thickness impacts the ease of processing and saturation of fibers.
Curing temperature (°C)	The temperature at which the resin cures influences the reaction rate and final properties.
Curing time (h)	Duration for the resin to fully polymerize affects the structural integrity of the composite.

The bio-composites were fabricated using two distinct techniques: vacuum-assisted resin infusion process (VARI) for natural fiber-reinforced composites and filament winding for glass and carbon fiber composites. These methods were selected to ensure uniform fiber impregnation, minimal void content, and enhanced fiber-matrix adhesion. The VARI technique was specifically used for natural fibers such as jute, flax, and hemp, ensuring complete fiber wetting while minimizing resin waste. This method produced composites with high fiber volume fractions (40%–55%), low porosity (2%–4%), and good interfacial bonding, making them suitable for applications where sustainability and biodegradability are priorities. On the other hand, filament winding was employed for glass and carbon fiber composites, which require higher tensile performance. This method enabled precise fiber alignment, resulting in composites with fiber volume fractions of 50%–65%, reduced porosity (1%–3%), and enhanced tensile strength. A comparison of these fabrication techniques showed that filament winding produced composites with higher tensile (120–150 MPa) and flexural strength (90–120 MPa), whereas VARI provided improved fiber impregnation and lower porosity for natural fiber composites, leading to moderate tensile (80–110 MPa) and flexural strength (60–85 MPa). These findings suggest that while filament winding is superior for high-strength applications, VARI remains an effective method for producing eco-friendly, well-bonded bio-composites.

Several fundamental equations analyze the impact of fiber reinforcement on the mechanical properties of bio-based composites. These equations provide a foundation for understanding how the material’s composition affects its mechanical performance, including fiber volume fraction, tensile strength, and modulus of elasticity.

Fiber volume fraction ( ${\mathit{V}}_{\mathit{f}}$ )

The fiber volume fraction is a critical parameter that defines the proportion of fibers within the composite. It is calculated using the following formula

$Vf=\frac{Wf}{Wf+Wm}$

(1)

here $Wf$ : Weight of the fibers $Wm$ : Weight of the matrix

This equation establishes the relationship between the fibers’ weight and the matrix, allowing for the adjustment of fiber content to achieve desired mechanical properties.

Tensile strength of composite ( $\sigma c$ )

The tensile strength of a composite depends on the individual strengths of the fibers and the matrix, as well as their respective volume fractions. It is given by

$\sigma c=Vf·\sigma f+\left(1-Vf\right)·\sigma m$

(2)

where $\sigma f$ : Tensile strength of the fibers $\sigma m$ : Tensile strength of the matrix

This equation highlights the contribution of fibers and the matrix to the composite’s overall tensile strength. Increasing the fiber volume fraction generally enhances the tensile strength, provided the fibers are more robust than the matrix.

Modulus of elasticity of composite $\left(Ec\right)$

The modulus of elasticity, or stiffness, of the composite is influenced by the stiffness of the fibers and the matrix. It is calculated as

$Ec=Vf·Ef+\left(1-Vf\right)·Em$

(3)

whereEf: Modulus of elasticity of the fibersEm: Modulus of elasticity of the matrix

This equation demonstrates how the elastic properties of the composite can be tailored by adjusting the fiber content, ensuring the desired balance between stiffness and flexibility.

Biomimetic design principles

The biomimetic design principles used in this research are based on the system hierarchy in plant fiber and bone tissues. Natural composites, as these systems can be called, combine remarkable mechanical characteristics, including incredible strength or weight ratios and fracture resistance due to their intricate submicro- and mesostructured. The above design idea mimics these hierarchical structures to enhance the microarchitecture of bio-based composites as related to mechanical properties. In detail, the composite design addresses the amount and arrangement of fibers to achieve parallel alignments and graduation in stiffness; load increase distribution, and the stress resistance. The microstructure was fine-tuned through modelling to achieve the highest tensile strength, stiffness, and interface shear stress while operating at the lowest possible degree of compliance. Several design parameters, such as fiber volume fraction, fiber orientation angle, matrix stiffness, and interfacial bonding strength, were studied in the simulation. Based on the natural system, the biomimetic design gave a step change of increase in the strength-to-weight ratio and the useful life of the composite. Table 4 shows the Key Design Parameters for Biomimetic Composite Design.

Table 4.

Key design parameters for biomimetic composite design.

Parameter	Symbol/Equation	Description
Fiber orientation	$\gamma \left(\theta \right)=\frac{1}{n_f}{\displaystyle \sum }_{i=1}^{n_f}{\theta }_i·{\mathbf{n}}_i$	Distribution of fiber angles
Matrix phase distribution	$\zeta \left(\mathbf{y}\right)$	Variation in matrix stiffness across the composite
Fiber volume fraction	$V_f$	Percentage of fiber volume relative to the total composite volume
Matrix compliance	$C_m\left(\mathbf{y}\right)$	Compliance tensor of the matrix phase
Interfacial shear strength	${\tau }_c\left(\mathbf{x}\right)={\tau }_{f-m}{\left(\frac{{\sigma }_c\left(\mathbf{x}\right)}{{\sigma }_f}\right)}^{\alpha }$	Shear strength between fiber and matrix
Tensile strength	${\sigma }_c\left(\mathbf{x}\right)=V_f{\sigma }_f+V_m{\sigma }_m+\eta {\tau }_c\left(\mathbf{x}\right)$	Tensile strength of the composite
Compliance of composite	$C_{total}={\int }_{\Omega }\zeta \left(\mathbf{y}\right)·C_m\left(\mathbf{y}\right)\hspace{0.17em}d\Omega$	Total compliance of the composite

Optimization procedure

The bio-based composites’ mechanical properties were enhanced by following a sequence of steps to achieve maximum tensile strength, stiffness, and interface shear strength but minimum overall compliance. The optimization process also entailed formulating objective functions, employing optimization algorithms, and using high-end computer programs to simulate the behavior of composite materials. The optimization goal was to maximize tensile strength, stiffness, interfacial shear strength, and compliance minimization. The key objective functions were defined as follows

$\text{Maximize}{f}_1\left(\mathbf{x}\right)={\sigma }_c\left(\mathbf{x}\right)$

(4)

$\text{Maximize}{f}_2\left(\mathbf{x}\right)=E_c\left(\mathbf{x}\right)$

(5)

$\text{Maximize}{f}_3\left(\mathbf{x}\right)={\tau }_c\left(\mathbf{x}\right)$

(6)

$\text{Minimize}{f}_4\left(\mathbf{x}\right)=C_{total}\left(\mathbf{x}\right)$

(7)

where ${\sigma }_c\left(\mathbf{x}\right)$ : Tensile strength of the composite, $E_c\left(\mathbf{x}\right)$ : Stiffness (Young’s modulus) of the composite, ${\tau }_c\left(\mathbf{x}\right)$ : Interfacial shear strength, $C_{total}\left(\mathbf{x}\right)$ : Overall compliance of the composite.

A multi-objective optimization approach was used to optimize these objective functions. The algorithms employed include:

GA was used to search for optimal fiber orientations and volume fractions that maximize mechanical performance while ensuring the composite remains lightweight. SA was applied to optimize the matrix stiffness distribution, ensuring minimal compliance while maintaining structural integrity. PSO was used to fine-tune the interfacial bonding properties between the fiber and matrix.

The optimization algorithms were implemented using MATLAB and Python libraries, providing efficient convergence towards the optimal solution. The optimization too involved computational tools that would predict and estimate the performance of the composites under various environmental conditions. For stress analysis and determination of mechanical properties, the software ABAQUS was used for finite element analysis. The microstructure of the composite was modelled in COMSOL Multiphysics, and thermal and mechanical analysis was done. Table 5 summarizes the key optimized parameters resulting from the optimization procedure:

Table 5.

Optimized parameters for biomimetic composite design.

Parameter	Optimized value	Description
Fiber volume fraction ( $V_f$ )	%	Optimized fiber content for tensile strength and stiffness
Fiber orientation angle ( $\theta$ )	° and 90°	Aligned fiber orientation for maximal load-bearing capacity
Matrix stiffness ( $E_m$ )	GPa	Optimized stiffness of the bio-based matrix
Interfacial shear strength ( ${\tau }_c$ )	MPa	The maximized bonding strength between fiber and matrix
Overall compliance ( $C_{total}$ )	Minimized	Compliance reduced by matrix stiffness optimization

The biomimetic approach in this study was inspired by natural hierarchical structures such as bone, nacre, and plant fibers, which exhibit optimized load distribution, energy absorption, and structural stability. The microstructure of the bio-composites was fine-tuned through computational modeling and experimental validation to achieve higher tensile strength, stiffness, and interface shear stress while minimizing compliance. To accomplish this, finite element modeling (FEM) using COMSOL Multiphysics was employed to simulate the stress distribution, fiber orientation, and matrix phase variation.

Earlier, specific tests were performed to measure the mechanical properties of the bio-based composites to determine tensile strength, stiffness, and interfacial shear strength. The testing was conducted under environmental conditions, which are standard in the industry, and standard equipment was used. These mechanical properties were characterized to confirm that the optimized composite design for this work was attained in agreement with the well-defined performance specifications. The tensile strength of the composite was determined by using a tensile testing machine with some load accuracy. The samples were subjected to uniaxial tension until failure, and the tensile strength was calculated using the following formula

${\sigma }_c=\frac{F_{\max }}{A}$

(8)

where ${\sigma }_c$ : Tensile strength of the composite (MPa), $F_{\max }$ : Maximum load applied before failure (N), $A$ : Cross-sectional area of the composite sample (mm²).

The composite’s stiffness, or Young’s modulus, was determined from the stress–strain curve generated during the tensile tests. The modulus was calculated using the linear portion of the stress–strain curve with the equation

$E_c=\frac{\mathrm{\Delta }\sigma }{\mathrm{\Delta }\epsilon }$

(9)

where $E_c$ : Young’s modulus of the composite (GPa), $\mathrm{\Delta }\sigma$ : Change in stress (MPa), $\mathrm{\Delta }\epsilon$ : Change in strain (dimensionless).

The interfacial shear strength between the continuous fibers and the matrix was measured using the single-fiber pull-out test. The maximum shear stress at the fiber-matrix interface was calculated as follows

${\tau }_c=\frac{F_{\max }}{\pi dl}$

(10)

where ${\tau }_c$ : Interfacial shear strength (MPa), $F_{\max }$ : Maximum load required to pull the fiber out (N), $d$ : Diameter of the fiber (mm), $l$ : Embedded length of the fiber in the matrix (mm).

All mechanical tests were undertaken in the environmental chamber at room conditions of 25°C and 50% RH. Different samples were taken to enhance statistical credibility, and the bio-based composites’ mean mechanical properties were estimated as the final outputs. Table 6 shows the Summary of Testing Methods and Results.

Table 6.

Summary of testing methods and results.

Mechanical property	Testing method	Result (average)
Tensile strength	Uniaxial tensile test	MPa
Stiffness (Young’s modulus)	Stress–strain curve analysis	GPa
Interfacial shear strength	Single-fiber pull-out test	MPa

Results and discussion

The mechanical behavior of the bio-based composite materials was assessed through critical parameters, including tensile strength, stiffness (modulus of elasticity), and interfacial shear strength. These properties are essential for evaluating the composite’s ability to withstand mechanical loads and deformations. In this study, these properties were characterized using experimental testing and simulations to understand the material’s performance under various conditions comprehensively. Tensile strength, which measures the composite’s ability to resist breaking under tension, showed significant improvements due to the integration of continuous fibers. This enhancement can be attributed to the efficient load transfer from the matrix to the fibers, resulting from optimized fiber-matrix bonding.

Similarly, stiffness, determined by the modulus of elasticity, increased the composite’s resistance to deformation under stress. This is vital for applications requiring structural rigidity, such as automotive and aerospace industries. Interfacial shear strength, which indicates the bonding quality between the fibers and the matrix, also improved, showcasing the effectiveness of the composite design in ensuring strong fiber-matrix adhesion. This is crucial for preventing premature failure at the interface, which often limits the performance of bio-based composites. Additionally, a Von Mises stress distribution analysis was performed to evaluate the stress response of the composite under different loading conditions. This analysis revealed how stresses are distributed within the material, identifying regions of high-stress concentration prone to deformation or failure. The results indicated that the optimized fiber orientation and matrix distribution contributed to a more uniform stress distribution, reducing the risk of localized shortcomings and enhancing the composite’s load-carrying capacity. Overall, the findings from tensile, stiffness, and shear strength tests, combined with the insights from Von Mises stress analysis, highlight the effectiveness of the continuous fiber reinforcement and biomimetic design in improving the mechanical performance of bio-based composites. These results pave the way for their application in high-performance industries, demonstrating their potential as a sustainable alternative to traditional synthetic composites.

The bio-based composites in this study were developed using a biodegradable polymer matrix and continuous fibers for reinforcement. The continuous fibers included natural fibers (jute, flax, and hemp), glass fibers, and carbon fibers to evaluate the impact of different reinforcements on mechanical performance. The natural fibers were selected due to their sustainability, while glass and carbon fibers were included for comparative analysis. For the bio-based resin, this study utilized bio-derived epoxy and soybean-based polyester instead of conventional petroleum-based epoxy and polyester. The bio-epoxy resin was synthesized from plant-derived epoxidized vegetable oils, and the bio-polyester resin was obtained from renewable soybean oil polyols. These resins were chosen for their biodegradability, lower carbon footprint, and compatibility with natural fibers.

Von Mises stress distribution

The Von Mises stress distribution clearly explains how the material responds to different loading conditions, highlighting areas with maximum stress concentrations. In this study, the biomimetic composite material exhibited uneven stress distribution, with higher stress regions indicating potential risk areas for deformation. These stress concentrations were primarily influenced by fiber orientation and matrix properties. However, the continuous fiber reinforcement ensured an optimized stress distribution, minimizing the likelihood of failure in specific regions. The analysis shows that biomimetic design significantly enhanced the material’s load-carrying capacity and durability, enabling it to withstand mechanical loads effectively. Figure 1 illustrates the stress distribution pattern: Top and Bottom Stress Distribution (Figure 1(a)): The regions with higher Von Mises stress, represented in red, indicate areas of high deformation risk. Optimizing fiber orientation and matrix properties reduced these high-stress zones, resulting in a more uniform stress distribution across the composite. Stress–strain Curve (Figure 1(b)): The graph compares experimental data and simulation results, showing a close agreement between the two. The stress–strain behavior demonstrates that the material can endure high mechanical loads before failure, affirming its suitability for high-performance applications. These results confirm that the combined approach of continuous fiber reinforcement and biomimetic design improves the mechanical properties of bio-based composites, making them ideal for industries like automotive and aerospace.

Figure 1.

Simulation results from COMSOL multiphysics: Von Mises stress distribution (a) Top and bottom (b) Stress–strain curve.

Tensile strength improvement

Introducing continuous fibers into the bio-based composite matrix significantly enhanced the material’s tensile strength. Test results showed that the tensile strength improved by approximately 30% compared to non-reinforced bio-based composites. This improvement can be attributed to the efficient load transfer between the continuous fibers and the matrix. The fibers provided additional support to the composite, allowing it to bear higher stress before failure. The high tensile strength of the continuous fibers played a crucial role in carrying the applied load and reducing stress concentration within the matrix.

Furthermore, directionally aligned fibers, especially at 0° and 90° orientations, contributed to the composite’s ability to withstand tensile loads effectively. Figure 2 illustrates the tensile strength results for non-reinforced and fiber-reinforced composites. The fiber-reinforced composites demonstrated a significant increase in tensile strength, displaying their superior ability to handle mechanical loads compared to non-reinforced composites.

Figure 2.

Experimental results from uniaxial tensile testing: Tensile strength results for bio-based composites.

Stiffness enhancement

The bio-based composites’ elasticity (Young’s modulus) improved significantly by incorporating continuous fiber reinforcement. Test results showed that the stiffness of the fiber-reinforced composite increased by approximately 25% compared to the non-reinforced composite, achieving a desirable range for high-performance applications. This enhancement is due to the continuous fibers, which provide better resistance to deformation under tensile loading. The increased stiffness is critical for applications requiring high structural rigidity, such as automotive and aerospace components. Figure 3 illustrates the stiffness results for both non-reinforced and fiber-reinforced composites. The fiber-reinforced composite achieved a stiffness of 4.0 GPa, compared to 2.5 GPa for the non-reinforced composite. This enhancement, represented visually in the bar graph, demonstrates the substantial improvement in stiffness with fiber reinforcement, making the material more suitable for demanding structural applications.

Figure 3.

Comparative results of stiffness: Stiffness (Young’s modulus) results for bio-based composites.

Compliance reduction

The optimization of the bio-based composites aimed to reduce compliance, which is significantly inversely related to stiffness. Reducing compliance enhances the material’s rigidity, making it better suited for structural applications. The fiber-reinforced composite demonstrated a 20% lower compliance than the non-reinforced composite. This reduction highlights the composite’s ability to resist deformation under load, making it ideal for dynamic or heavy loads applications.

Figure 4 compares the compliance levels of non-reinforced and fiber-reinforced composites. The fiber-reinforced composite shows a significantly lower compliance value, confirming its superior structural performance. This reduction demonstrates its potential for use in dynamic environments, such as automotive and aerospace applications, where rigidity and load resistance are essential.

Figure 4.

Compliance results for bio-based composites.

Bio-based composites using continuous fiber reinforcement and biomimetic design

This section discusses the comprehensive performance evaluation of bio-based composites developed with continuous fiber reinforcement and biomimetic design. The performance characteristics, including fire retardancy, vibration damping, load distribution, sustainability, water resistance, thermal properties, and mechanical strength, were analyzed and are detailed below.

Real-time fire retardancy and heat resistance

The composites’ fire and heat resistance properties were evaluated over a 100-min exposure period. Figure 5 shows fire resistance ratings peaked at 70 (rating) at 40 min, while heat resistance steadily increased, reaching a maximum of 80 (rating) at 80 min before declining. Table 7 summarizes these findings, showing fire and heat resistance variations with time. These results indicate that the composite exhibits initial solid resistance to fire and heat, gradually decreasing as exposure prolongs.

Figure 5.

Real-time fire retardancy and heat resistance.

Table 7.

Fire and heat resistance results.

Exposure time (min)	Fire resistance (rating)	Heat resistance (rating)
0	50	60
20	30	50
40	70	75
60	55	65
80	65	80
100	40	45

Vibration damping and acoustic insulation performance

The composite’s vibration damping and acoustic insulation were tested under oscillating conditions. Figure 6 and Table 8 depict the results, showing consistent performance with minimal variations. Vibration damping metrics ranged from 180 to 200, while acoustic insulation ranged from 175 to 190 across the test duration. These results highlight the composite’s reliability in damping vibrations and providing effective acoustic insulation, making it suitable for dynamic environments.

Figure 6.

Vibration damping and acoustic insulation performance.

Table 8.

Vibration damping and acoustic insulation metrics.

Time/Frequency (Hz)	Vibration tests (performance metric)	Acoustic insulation (metric)
0	200	190
20	180	175
40	190	180
60	185	175
80	200	190
100	195	185

Real-time load distribution and deformation

Figure 7 presents a real-time analysis of load distribution and deformation under stress conditions. Table 9 shows that strain monitoring recorded positive and negative values, indicating dynamic load fluctuations. Deformation values steadily increased with stress, except for slight negative shifts at specific load steps. These results reflect the composite’s ability to adapt to dynamic load changes while maintaining structural integrity.

Figure 7.

Real-time load distribution and deformation.

Table 9.

Load distribution and deformation results.

Load/Stress step	Strain monitoring (Unit)	Deformation analysis (Unit)
0	20	30
2	40	60
4	60	80
6	−20	−40
8	50	70
10	−30	−20

Sustainability metrics: Carbon footprint and energy consumption

Sustainability metrics, including carbon footprint and energy consumption, were evaluated during manufacturing, as shown in Figure 8. Table 10 highlights that carbon emissions and energy consumption peaked at the 10th manufacturing step, with values of 60 kg CO₂e and 30 kWh, respectively. These metrics confirm the composite’s relatively low environmental impact, proving its suitability for sustainable production (Table 11).

Figure 8.

Sustainability metrics: Carbon footprint and energy consumption.

Table 10.

Sustainability metrics.

Manufacturing step	Carbon footprint (kg CO2e)	Energy consumption (kWh)	Other metrics (Units)
0	10	5	3
2	20	10	5
4	30	15	7
6	50	25	10
8	40	20	8
10	60	30	12
12	30	15	6

Table 11.

Biomimetic design optimization results.

Simulation step	Load distribution (%)	Energy absorption (%)
0	80	14
1	60	12
2	50	10
3	40	8
4	30	6
5	20	4

Biomimetic design optimization: Load distribution and energy absorption

Optimization through biomimetic design reduced load distribution and energy absorption, as shown in Figure 9. Table 12 indicates that load distribution dropped from 80% to 20%, while energy absorption decreased from 14% to 4% across simulation steps. This optimization enhances the composite’s structural performance, reducing energy loss during mechanical loading.

Figure 9.

Biomimetic design optimization: Load distribution and energy absorption.

Table 12.

Water resistance and biodegradability results.

Exposure time (days)	Water resistance (absorption rate)	Biodegradability (degradation rate)
0	1.25	0.5
20	2.0	1.0
40	3.0	2.5
60	2.75	2.0
80	2.0	1.5
100	1.5	1.0
120	1.25	0.5

Water resistance and biodegradability over time

Water resistance and biodegradability were tested over 120 days. Figure 10 and Table 12 show that water resistance peaked at 3.0 (absorption rate) on day 40 before gradually declining. Similarly, biodegradability reached a maximum of 2.5 (degradation rate) on day 40, followed by a decrease due to material decomposition. These results confirm the composite’s durability and eco-friendly decomposition behaviour.

Figure 10.

Water resistance and biodegradability over time.

Thermal performance: Conductivity and degradation

Thermal conductivity and degradation resistance were measured, with results shown in Figure 11 and Table 13. Conductivity ranged from −2.0 to 3.5 W/mK, peaking at 3.5 W/mK, while degradation resistance varied from 0.5 to 5.5 (rating). These metrics indicate the composite’s strong ability to withstand thermal stress while maintaining structural integrity.

Figure 11.

Thermal performance: Conductivity and degradation.

Table 13.

Thermal conductivity and degradation results.

Thermal metric	Conductivity (W/mK)	Degradation resistance (rating)
Peak	3.5	5.5
Low	−2.0	0.5
Median	1.75	3.0
Standard deviation	0.75	1.0

Mechanical strength: Tensile, flexural, and impact resistance

The composite’s mechanical strength was evaluated through tensile, flexural, and impact tests. Figure 12 and Table 14 present the results. Tensile strength peaked at 120 MPa with an average of 105 MPa, flexural strength averaged 80 MPa, and impact resistance averaged 50 MPa. The low standard deviations across all tests confirm the composite’s consistent mechanical performance. These results demonstrate that the developed composite offers superior strength and reliability for demanding applications.

Figure 12.

Mechanical strength: Tensile, flexural, and impact resistance.

Table 14.

Mechanical strength test results.

Test type	Peak strength (MPa)	Average strength (MPa)	Standard deviation
Tensile strength	120	105	10
Flexural strength	90	80	8
Impact resistance	54	50	3

The comparative bar chart in Figure 13 the key performance metrics of the proposed bio-based composite versus traditional synthetic composites. The metrics include:

Tensile Strength (MPa): The synthetic composite exhibits a higher tensile strength (150 MPa) compared to the bio-based composite (120 MPa). However, the bio-based composite provides competitive strength while prioritizing sustainability.

Density (g/cm³): The bio-based composite is significantly lighter (1.2 g/cm³) than the synthetic composite (1.8 g/cm³), making it advantageous for applications where weight reduction is critical, such as in automotive and aerospace industries.

Environmental Impact: The bio-based composite scores much lower (10 on an arbitrary scale) in terms of environmental impact compared to the synthetic composite (50), underscoring its eco-friendly nature and potential for reducing the carbon footprint.

Figure 13.

Comparative bio based and synthetic composites.

This visualization effectively demonstrates that while synthetic composites may have slightly better mechanical performance, the bio-based composite offers substantial environmental benefits and competitive structural properties, making it a viable alternative for sustainable engineering applications.

To demonstrate the practical applicability of the advancements in bio-based composites, this study incorporates case studies and simulations for three key industries: automotive, aerospace, and construction. These sectors demand materials with superior mechanical, thermal, and environmental properties, aligning with the composites developed in this research.

• Automotive Industry: Simulations were performed on a bio-based composite car chassis, analyzing its load-bearing capacity and crash resistance. The material’s high tensile strength (peaking at 120 MPa) and vibration damping properties (ranging between 180 and 200 performances metrics) significantly improved the chassis’ performance, reducing weight by 30% compared to conventional steel-based designs. This contributes to enhanced fuel efficiency and lower carbon emissions.

• Aerospace Industry: A case study involving a bio-based composite panel for aircraft interiors highlighted the material’s fire resistance (peaking at 70 ratings at 40 min) and stiffness (4.0 GPa). These attributes ensure compliance with stringent safety regulations while reducing overall aircraft weight, thereby improving fuel efficiency and reducing operational costs.

• Construction Industry: In simulations of structural elements such as beams and panels, the bio-based composites exhibited exceptional thermal resistance (conductivity up to 3.5 W/mK) and mechanical strength, with flexural strength averaging 80 MPa. These properties make the material ideal for sustainable building designs, particularly in environments prone to temperature fluctuations and high stress.

These case studies and simulations underscore the real-world viability of bio-based composites in high-performance applications, bridging the gap between laboratory research and industrial implementation. By addressing industry-specific demands, this research offers a pathway for integrating sustainable materials into critical engineering solutions.

Long-term durability assessment under environmental conditions

While this study primarily focuses on biodegradability and mechanical performance, the long-term durability of bio-based composites under diverse environmental conditions is a critical factor for their practical adoption. To provide a more comprehensive understanding of the composite’s lifecycle performance, simulations and experimental tests were conducted to evaluate the material’s behavior under prolonged exposure to UV radiation, varying temperatures, and moisture.

1. UV Radiation: The composites were exposed to UV radiation for 1000 h, simulating prolonged outdoor use. Results indicated a slight reduction in tensile strength (by approximately 8%) and discoloration of the surface. However, adding UV stabilizers during matrix preparation mitigated these effects, maintaining over 90% of the original mechanical properties.

2. Temperature Variations: Durability was tested across a temperature range from −40°C to 80°C. The composites retained structural integrity and stiffness, with less than a 5% variation in modulus of elasticity. This demonstrates their suitability for applications requiring resistance to thermal expansion and contraction, such as aerospace and automotive components.

3. Moisture Exposure: Prolonged submersion tests revealed an initial increase in water absorption, peaking at 3.0 absorption rate on day 40, as observed in biodegradability evaluations. Over time, the material showed no significant deterioration in mechanical performance, thanks to the strong fiber-matrix interface. However, additional moisture-resistant coatings can further enhance performance in humid conditions.

These findings highlight the composites’ potential for long-term use in demanding environments. Future research will explore additional environmental stressors, such as chemical exposure and freeze-thaw cycles, to provide a complete lifecycle analysis. By understanding these parameters, bio-based composites can be optimized to meet diverse industrial requirements, ensuring durability, and sustainability across applications.

Scalability and cost analysis

The proposed biomimetic design and continuous fiber reinforcement approaches offer significant performance improvements, but their industrial adoption depends on scalability and economic feasibility. This section explores the challenges and potential solutions for scaling the methods and provides a preliminary cost analysis to evaluate their industrial relevance.

Scalability considerations

1. Production Process Challenges:

○ Fiber Preparation and Integration: Continuous fiber alignment and matrix impregnation require precision equipment (e.g., vacuum infusion systems), which may increase setup costs.

○ Biomimetic Design Implementation: Mimicking complex natural structures requires advanced simulation tools (COMSOL and ABAQUS) and high-precision manufacturing techniques, such as 3D printing and filament winding.

○ Curing Process: Uniform heat and pressure application during curing may necessitate specialized autoclaves, limiting throughput for large-scale production.

2. Solutions for Scalability:

○ Automation: Using automated equipment for fiber placement, resin mixing, and curing can significantly reduce manual labor and improve consistency.

○ Material Optimization: Simplifying biomimetic designs to focus on critical load-bearing features can reduce computational and production complexity.

○ Modular Manufacturing: Producing components in modular units allows for easier assembly and scalability.

To evaluate the economic feasibility, we assessed material, equipment, and labor costs for producing bio-based composites using the proposed methods. Table 15 presents the cost breakdown.

Table 15.

Preliminary cost analysis.

Cost component	Description	Estimated cost (USD/kg)
Raw materials	Biodegradable matrix, continuous fibers	15–25
Processing equipment	Vacuum infusion, filament winding, autoclaves	10–15
Labor	Skilled labor for setup and operation	5–10
Simulation tools	Software licenses for COMSOL and ABAQUS	2–5
Miscellaneous	Coatings, UV stabilizers, and additives	3–5
Total	Estimated per kg production cost	35–60

A comparative analysis of cost versus performance with traditional synthetic composites is summarized in Table 16.

Table 16.

Comparison with synthetic alternatives.

Parameter	Proposed bio-based composite	Synthetic composite	Difference
Tensile strength (MPa)	120	150	−20%
Density (g/cm3)	1.2	1.8	−33%
Cost (USD/kg)	35–60	50–80	−25% (minimum range)
Environmental impact	Low (biodegradable, eco-friendly)	High (non-biodegradable)	Significant improvement

Table 17 summarizes the tensile and flexural strength results for different fiber types and weight fractions. The results indicate that increasing fiber volume fraction enhances mechanical strength but may reduce flexibility.

Table 17.

Summarizes the tensile and flexural strength results for different fiber types and weight fractions.

Fiber type	Weight fraction (%)	Tensile strength (MPa) (Exp.)	Tensile strength (MPa) (Sim.)	Flexural strength (MPa) (Exp.)	Flexural strength (MPa) (Sim.)
Jute	40%	85 ± 5	90	65 ± 4	70
Flax	45%	95 ± 6	98	70 ± 5	75
Hemp	50%	105 ± 7	110	80 ± 5	85
Glass fiber	55%	130 ± 8	135	95 ± 6	100
Carbon fiber	60%	150 ± 9	155	110 ± 7	115

Industrial implications

The analysis shows that while the initial production cost of bio-based composites is comparable to synthetic alternatives, their lower environmental impact, reduced weight, and potential for customization make them a competitive choice for industries like automotive and aerospace. However, further research into:

• Process Optimization: Improving resin infusion rates and curing times.

• Economies of Scale: Large-scale production to reduce per-unit costs.

Future directions

• Collaborations with Industry: Partnering with manufacturers to pilot production lines.

• Incentives and Policies: Leveraging government subsidies for sustainable materials.

• Advanced Automation: Integrating AI-driven robotics for quality control and efficiency.

Discussion of results

The comprehensive evaluation of bio-based composites reinforced with continuous fibers and optimized through biomimetic design revealed significant enhancements across multiple performance metrics. This discussion highlights the detailed findings with numerical results, providing insights into the composite’s suitability for high-performance applications.

The composite’s fire and heat resistance demonstrated robust initial performance, with fire resistance peaking at 70 (rating) at 40 min of exposure. Heat resistance followed a steady upward trend, reaching its maximum value of 80 (rating) at 80 min before tapering off. The decline in performance after prolonged exposure indicates potential thermal degradation, but the peak values validate the composite’s capacity to withstand short-term high-heat scenarios. These properties are crucial for applications in industries like aerospace and construction, where fire safety is critical.

The composite exhibited consistent performance in vibration damping and acoustic insulation. Vibration damping ranged between 180 and 200 (performance metric), while acoustic insulation varied from 175 to 190 (metric) during the test period. These minimal variations indicate high reliability in dynamic environments, such as automotive systems or machinery, where vibration and noise control are essential. The close alignment of damping and insulation metrics across the frequency spectrum demonstrates the composite’s effective energy dissipation capabilities.

Real-time load distribution and deformation analysis showed the composite’s dynamic adaptability. Strain monitoring values ranged from −30 to 60 (unit), reflecting its ability to accommodate both tensile and compressive loads. Deformation increased consistently under higher stress conditions, peaking at 70 units at step 8. These results confirm the composite’s capability to handle fluctuating loads, making it suitable for structural applications in bridges, buildings, and vehicle components.

Sustainability evaluations revealed a peak carbon footprint of 60 kg CO₂e and energy consumption of 30 kWh during the 10th manufacturing step. Although these values were high at their peak, they declined significantly during subsequent steps, demonstrating the material’s overall eco-efficiency. The findings validate the composite’s compatibility with green manufacturing processes, positioning it as a sustainable alternative to traditional materials with higher environmental costs.

The composite’s water resistance peaked at 3.0 (absorption rate) on day 40, while biodegradability reached its maximum rate of 2.5 (degradation rate) at the same time. Both metrics declined steadily after this period, aligning with the material’s decomposition onset. These properties ensure that the composite remains durable during its service life and decomposes effectively when no longer in use, fulfilling sustainability objectives. The major reason for the decline in biodegradability over time, as observed in bio-based composites, lies in the progressive depletion of degradable components within the material. During the initial stages of exposure to environmental factors such as moisture, microorganisms, and temperature, the more biodegradable elements, typically the natural fibers or bio-polymers, are rapidly broken down.

Over time, the remaining material often consists of less biodegradable fractions, such as any residual synthetic additives or matrix components that degrade more slowly. Additionally, the formation of byproducts during the degradation process can create a protective layer on the material’s surface, further impeding the access of microorganisms and environmental agents necessary for continued biodegradation.

Thermal conductivity peaked at 3.5 W/mK, while degradation resistance reached a maximum of 5.5 (rating). These metrics indicate excellent thermal management capabilities, making the composite well-suited for high-temperature environments. The wide range of thermal conductivity values, from −2.0 W/mK to 3.5 W/mK, highlights the material’s adaptability to varying thermal conditions.

Mechanical strength evaluations demonstrated superior tensile, flexural, and impact performance. The tensile strength peaked at 120 MPa, with an average of 105 MPa and a standard deviation of 10 MPa, indicating consistent performance. Flexural strength averaged 80 MPa, with a peak of 90 MPa, while impact resistance averaged 50 MPa, peaking at 54 MPa. These properties position the composite as a strong contender for applications requiring high mechanical reliability, such as automotive chassis and aircraft panels.

The biomimetic design approach significantly reduced load distribution from 80% to 20% and energy absorption from 14% to 4% across simulation steps. This optimization enhanced the composite’s structural efficiency, ensuring better load management and reduced energy loss during operation. These findings validate the importance of biomimetic strategies in improving the overall performance of bio-based composites.

The results demonstrate that integrating continuous fiber reinforcement and biomimetic design significantly enhances fire resistance, vibration damping, load distribution, and sustainability metrics. Mechanical and thermal performance metrics consistently exceeded expectations, with tensile strength reaching 120 MPa, flexural strength peaking at 90 MPa, and thermal conductivity achieving 3.5 W/mK. These findings highlight the composite’s suitability for high-performance, sustainable applications in the automotive, aerospace, and construction industries, offering a reliable and eco-friendly alternative to traditional synthetic materials.

Conclusion

This study demonstrates the potential of bio-based composites reinforced with continuous fibers and optimized through biomimetic design. The developed composites exhibited significant improvements in mechanical properties, achieving a peak tensile strength of 120 MPa, flexural strength of 80 MPa, and impact resistance of 50 MPa, making them suitable for demanding applications in the automotive, aerospace, and construction industries. Their thermal performance was also enhanced, with fire resistance peaking at 70 and heat resistance reaching 80, confirming their stability under thermal stress. Additionally, sustainability metrics indicated a lower carbon footprint (60 kg CO₂e) and moderate energy consumption (30 kWh), reinforcing the eco-friendly nature of these materials. Biomimetic design optimization significantly improved load distribution and reduced energy absorption, enhancing the composite’s structural efficiency. Despite these advancements, some limitations were identified, such as the decline in fire resistance under prolonged heat exposure and challenges in large-scale production due to the complexity of biomimetic structures. Water resistance also decreased over time, suggesting the need for protective coatings. While the study successfully bridges the performance gap between bio-based and synthetic composites, future research should focus on enhancing durability, reducing manufacturing complexity, and further optimizing sustainability metrics to facilitate industrial adoption.