Design Of Composite Materials Research Articles

Constructing High-Performance Composite Epoxy Resins: Interfacial π-π Stacking Interactions-Driven Physical Rolling Behavior of Silica Microspheres.

The intrinsic compromise between strength and toughness in composite epoxy resins significantly constrains their practical applications. In this study, a novel strategy is introduced, leveraging interfacial π-π stacking interactions to induce the "rolling behavior" of microsphere fillers, thereby facilitating efficient energy dissipation. This approach is corroborated through theoretical simulations and experimental validation. The resulting composite epoxy resin demonstrates an impressive 49.8% enhancement in strength and a remarkable 358.9% improvement in toughness compared to conventional epoxy resins, accompanied by substantially reduced hysteresis. Moreover, this system achieves reversible closed-loop recyclability and rapid repair capabilities. The preliminary demonstration of "force-temperature equivalence" further establishes a novel pathway for the design of high-performance composite epoxy materials.

Multishell hierarchical GCNF/PANI/NiCo-LDH nanofibers film for high-performance supercapacitors

In the domain of supercapacitor investigation, nickel cobalt layered double hydroxides (NiCo-LDH), regarded as a promising battery material, have garnered significant attention. However, the inherent drawbacks of low conductivity and pronounced agglomeration in single-component NiCo-LDH hinder the achievement of satisfactory overall performance. Thus, a key challenge remains in the rational design of multi-component composite materials incorporating NiCo-LDH, carbon materials, and conductive polymers to enhance their electrochemical properties. In this study, we successfully fabricated multishell hierarchical fiber films of GCNF/PANI/NiCo-LDH through simple wet-chemical approach. This novel architecture features graphene-coated electrospun carbon nanofibers (GCNF) serving as a self-supporting carbon framework, polyaniline (PANI) acting as the conductive layer, and NiCo-LDH contributing a high faraday capacity. Utilizing the enhanced cooperative effects between the various components, the enhanced GCNF/PANI/NiCo-LDH electrode exhibits remarkable specific capacity (347.1 mAh g-1, 2499 F g-1 at 1 A g-1) alongside exceptional rate performance (maintaining 56.5% capacity at 20 A g-1). Moreover, when an asymmetric supercapacitor (ACS) is constructed using active carbon (AC) as the cathode and GCNF/PANI/NiCo-LDH as the anode, it demonstrates remarkable energy storage capabilities. Specifically, it achieves an impressive energy capacity of 43.8 Wh kg-1, along with a high power exceptional durability, with a capacitance retention of 88.8% even after 2000 cycles. This study presents a novel approach for designing high-performance density of 937.5 W kg-1. Additionally, it exhibits core-triple-shelled hierarchical materials in the field of energy storage devices.

A computational study of the size effect of SiO2 spherical nanoparticles in water solvent.

This study comprehensively describes the interaction between SiO2 spherical nanoparticles and water molecules as a solvent medium. Our goal is to provide valuable insights into the significance of nanoparticle size in understanding their behavior and the resulting changes in the physical properties of materials. Our results indicate that SiO2 nanoparticles exhibit a strong affinity for water, which increases with the nanoparticle size. Our investigation can be relevant for the design of new composite materials with applications ranging from medical prostheses to quantum electronics, optoelectronic devices, catalysis, and photoluminescence. We have concentrated on the study of the amorphous, where size effects seem to be more pronounced. A computational study was carried out within the molecular dynamics simulations framework available in the GROMACS-v2019.2 software, with force fields consistent with DFTand the CHARMM36 utilized in the molecular description of the systems. The water model used was the TIP3P implemented in CHARMM36 force fields. A comprehensive analysis of molecular interactions of various system configurations was performed, including radial distribution function (RDF), mean square displacement (RMSD), hydrogen bonding analysis,interfacial analysis, andstudying system size'seffect on mechanical properties.

Comparative analysis of direct search methods for material design optimization

This paper contributes to the field of optimization for periodic composite material design by systematically evaluating the performance of four direct search algorithms: greedy, simulated annealing (SA), genetic algorithms (GA), and particle swarm optimization (PSO). The central goal is to determine the optimal arrangement of two material domains inside a representative volume element (RVE) while respecting the constraint that half volume of the domains is composed of a specific material, with the effective shear modulus as the objective function. The main contribution of this work is the detailed comparison of these algorithms in terms of success rates and computational efficiency, providing critical insights into their suitability for different problem scales. For a small-scale problem (16 cells), PSO achieves a 100% success rate, while SA demonstrates over 90% success but at a higher computational cost. The greedy algorithm, despite its simplicity, achieves a 72% success rate with the lowest computational effort, requiring an average of 256 objective function evaluations. GA, however, exhibits the lowest success rate at 52% and requires the highest average number of evaluations (5003.2). Furthermore, the paper extends the analysis to a more complex problem (36 cells), where the adaptability and efficiency of the algorithms are tested. This investigation highlights the trade-offs between algorithmic complexity, success rate, and computational cost, offering practical guidelines for selecting suitable optimization methods based on problem size and characteristics.

Inverse Identification of Constituent Elastic Parameters of Ceramic Matrix Composites Based on Macro–Micro Combined Finite Element Model

Accurate material performance parameters are the prerequisite for conducting composite material structural analysis and design. However, the complex multiscale structure of ceramic matrix composites (CMCs) makes it extremely difficult to accurately obtain their mechanical performance parameters. To address this issue, a CMC micro-scale constituents (fiber bundles and matrix) elastic parameter inversion method was proposed based on the integration of macro–micro finite element models. This model was established based on the μCT scan data of a plain-woven CMC tensile specimen using the chemical vapor infiltration (CVI) process, which could reflect the real microstructure and surface morphology characteristics of the material. A BP neural network was used to predict the multiscale stiffness, considering the influence of the porous structure on the macroscopic stiffness of the material. The inversion process of the constituent elastic parameters was established using the trust-region algorithm combined with an improved error function. The inversion results showed that this method could accurately invert the CMC constituent elastic parameters with excellent robustness and anti-noise performance. Under four different degrees of deviation in the initial iteration conditions, the inversion error of all parameters was within 1%, and the maximum inversion error was only 2.16% under a 10% high noise level.

Research on the design and thermal performance of vacuum insulation panel composite insulation materials

This study introduces a novel design methodology for composite insulation material aimed at reducing the operational energy consumption of buildings. Vacuum Insulation Panels (VIPs) are recognized for their excellent insulating properties due to their vacuum-sealed nature that minimizes thermal transmittance. However, VIPs are susceptible to damage from temperature stress and abrasion, which can compromise vacuum integrity and degrade performance over time. To mitigate this, a protective layer of rock wool board is adhered to the exterior of the VIP to create a composite insulation material. The thermal conductivity characteristics of the composite insulation materials are experimentally measured and then corroborated with simulations using ANSYS software to affirm the precision of finite element analysis methods. A composite Insulation wall model is constructed using ANSYS to analyze the impact of varying the thickness of the composite insulation materials and the pressure within the VIP on thermal performance. The findings demonstrate that the thermal transmittance coefficient of the composite insulated wall diminishes with increased insulation material thickness and rises with increased pressure within the VIP. Additionally, rock wool boards significantly enhance the durability of the composite insulation material.

A validated simulation methodology for determining single lap shear allowable strength in thermoplastic polymer composites

While several modeling approaches exist to simulate the strength of single lap shear configurations, their application to obtaining design allowables for thermoplastic composites remains underexplored. This paper addresses this gap by presenting a novel methodology for the forward propagation of parameter uncertainty using advanced finite element models specifically tailored for thermoplastic carbon fiber composites. The proposed approach goes beyond traditional methods by integrating advanced damage models and a structured validation process, supported by an extensive experimental test campaign.We demonstrate the feasibility of determining design allowables through simulation by examining the influence of batch size on both the validation process and the prediction of allowable strength. Our findings provide new insights into the propagation of uncertainties in the context of composite material design, showing that it is possible to achieve reliable design allowables through simulation, which can significantly accelerate the development of new components while maintaining high safety standards.

New Materials and Structures: Anti-Escape Trap Net for Trapping Eucryptorrhynchus brandti (Harold, 1880) (Coleoptera: Curculionidae).

The weevil Eucryptorrhynchus brandti (Harold, 1880), a wood-boring pest of Ailanthus altissima (Mill.) Swingle, has caused significant ecological damage and economic loss in China. Physical control was effective against the related species Eucryptorrhynchus scrobiculatus (Motschulsky). One type of trunk trap net controlled the adult weevil population through blocking and trapping. However, the effectiveness of this device was compromised by their tendency to escape when encountering such trapping nets. Therefore, it is crucial to enhance and optimize both the material composition and structural design of trap nets to enhance weevil capture rates by mitigating escape behavior. In this study, we compared the capture efficacy of an anti-escape trap net (AETN) with novel materials (Velcro) and a double-layer trap net (DLTN). The results indicate that the mean recapture rate of AETNs (50%) was significantly higher than that of DLTNs (3%) in laboratory tests. The total number of E. brandti captured using AETNs was 11 times higher than that of DLTNs in field marker recapture tests and 4 times higher in capture tests on field populations. The new AETN structures could effectively prevent the escape behavior of E. brandti and capture weevils. The use of Velcro made the AETN easier to manufacture, more convenient to use, and less costly. Overall, the AETN is an economical and environmentally friendly physical control device.

Hierarchical curing mechanism in epoxy/bismaleimide composites: Enhancing mechanical properties without compromising thermal stabilities

It remains a considerable challenge to enhance mechanical properties without sacrifice of thermal properties in epoxy-based materials. In this study, epoxy/bismaleimide (EP/BMI) composites were synthesized via a melting blend technique using 4,4′-diaminodiphenylsulfone as the curing agent. It is found that there is a unique hierarchical curing mechanism in EP/BMI systems, including (i) respective curing of EP and BMI monomer, (ii) copolymerization between EP prepolymer and BMI monomer, (iii) homopolymerization of EP prepolymer and BMI oligomer. Via the hierarchical copolymerization, EP and BMI are compatible without phase separation phenomenon. The copolymerization concurrently improved the composites’ resistance to deformation under stress and restricted the thermal mobility of the polymer chains upon heat. Compared to pure EP resin, EP/BMI composite (4:1) shows a flexural strength of 133.6 MPa, tensile strength of 106.4 MPa and toughness of 3.6 MJ/m3 respectively, increased by 20.7 %, 36.4 % and 45.0 %. Meanwhile, Tg and Yc were also improved by 10.3 ℃ and 12.3 % in EP/BMI composite. Furthermore, the mechanical and thermal properties of the EP/BMI composites can be efficiently tailored by curing conditions and EP:BMI molar ratios. This discovery provides a significant benchmark for the design of composite material and to expand the application horizons for both EP and BMI materials.

Study of mechanical properties of composite materials reinforced with aluminum fibers

This study investigates the mechanical properties of composite materials reinforced with aluminum fibers of varying lengths and concentrations. The research aims to evaluate the effects of fiber reinforcement on both flexural and compressive strengths, using fibers of three distinct lengths (2×20 mm, 2×30 mm, and 2×40 mm) and four different concentrations (0.5%, 1%, 1.5%, and 2%) by weight within the composite matrix. Mechanical tests were performed after 28 and 56 days of curing to assess the influence of fiber reinforcement over time. The results demonstrate that increasing fiber length and concentration generally improves the flexural and compressive strengths, with the most notable gains observed at moderate fiber content. However, the study also finds that excessively high fiber percentages may lead to diminishing returns in strength performance, possibly due to fiber agglomeration or stress concentration effects. These findings provide valuable insights into optimizing the design of fiber-reinforced composite materials for various structural applications, enhancing both performance and material efficiency.

Enhancing CO2 photoreduction to CO with 100 % selectivity by constructing heterojunctions and regulating open metal sites in Au/Fe3O4/MIL-101(Fe) catalysts

The widespread utilization of fossil fuels has resulted in a significant increase in CO2 emissions, leading to a variety of environmental issues. The photocatalytic conversion of CO2 into fuel presents an effective solution to both the energy crisis and environmental warming. Therefore, the selection of a suitable catalyst is paramount. However, traditional photocatalysts often encounter challenges such as rapid electron-hole recombination and limited exposure of active sites. To improve these limitations, this study introduces AFM-X, a heterojunction catalyst composed of Au/Fe3O4/MIL-101(Fe)-X, which facilitates the formation of open metal sites (OMS) that enhance the effective separation of photogenerated carriers. In AFM-X, OMS function as Lewis acid sites, thereby enhancing CO2 adsorption. The presence of Au nanoparticles (NPs) introduces additional active sites for CO2 reduction. The synergistic effect between OMS and Au NPs increases the catalyst’s active sites, while the heterojunction construction promotes electron transfer, thereby enhancing CO2 photocatalytic reduction efficiency. The CO generation rate of AFM-2 reached 98.8 μmol g−1 h−1, surpassing those of FM, MIL-101(Fe), Fe3O4, and Au NPs, by 4.1, 6.3, 6.2, and 3.2 times, respectively. Furthermore, AFM-2 maintains stable performance over a 40 h cycle test. In-situ DRIFTS spectroscopy reveals that CO2 reduction occurs through two parallel pathways. This study offers new insights into the design of composite photocatalytic materials, highlighting the effectiveness of OMS Lewis acid sites in significantly enhancing the photocatalytic reduction of CO2.

High-effective, convenient and environmental-friendly MOFs-chitosan-glyoxal composite film for ceftizoxime adsorption: Behavior and mechanisms

In this work, a novel PCN-222-chitosan-glyoxal (PCN@CSG22PCN@CSG: PCN-222-chitosan-glyoxal.) composite film was constructed by loading PCN-222 in chitosan substrate, and used for ceftizoxime adsorption. The results demonstrated that the PCN@CSG not only had excellent adsorption properties for ceftizoxime, but also maintained excellent structural properties in harsh environments (strong acids and alkalis), making it have good recycling performance. Specifically, the adsorption kinetics and isotherms investigation demonstrated that the adsorption process followed the pseudo-second-order kinetic model and Freundlich isotherm model respectively, indicating that it was a multilayer process mainly controlled by chemisorption. The PCN@CSG possesses excellent absorptive capacity of 561.7 mg·g−1 and reaches equilibrium rapidly within 60 min, which is attributed to the structural advantages of PCN-222 and chitosan. The amino, carboxyl and hydroxyl functional groups of PCN-222 provide numbers of active sites and cationic chitin greatly promoted the electrostatic adsorption with negative ceftizoxime. In addition, the PCN@CSG has the advantages of renewable and environment-friendly for the biodegradation of chitosan. After five consecutive adsorption-desorption cycles, the removal rate was still higher than 90 %, confirming the excellent reusability of PCN@CSG. This work provided a great prospect for the design and application of shaped-MOFs composite materials for the removal of cephalosporins in environmental water.

Construction of Asymmetric Filler Density Mixed-Matrix MOF Membranes via Liquid-Phase Ion Activation for Advanced Oxidation Processes.

Mixed-matrix membrane (MMM) reactors incorporating metal-organic framework (MOF) fillers have significant applications in fields such as separation, catalysis, and chiral resolution. However, the traditional method of directly mixing MOF fillers with polymers results in a symmetric structure where most of the MOF fillers are uniformly distributed across the membrane reactor's cross-section. During usage, this leads to a pronounced trade-off between flux and efficiency and the waste of the MOF, as the rich pore characteristics and active sites of MOFs are not fully utilized. In this study, we propose a liquid-phase ion activation strategy that enables the in situ formation of a uniform and densely packed MOF shell layer on the membrane surface during the phase inversion process of MMM fabrication. This asymmetric density distribution of the MOF-based MMM reactor selectively induces the generation of considerable nonradical 1O2 in the peroxomonosulfate (PMS) system, demonstrating superior catalytic degradation performance against antibiotics like TC and dye molecules (with a flux of 1880 L m-2 h-1 and a Kapp value of 648 min-1), as well as outstanding cycling stability and environmental tolerance. This discovery sheds light on the design and engineering of composite membrane materials and applications for advanced oxidation processes in water purification.

Harmonizing lightweight and ablation resistance: Design and performance of multilayer composite insulation materials for solid rocket motors

AbstractThe realization of lightweight insulation materials is often accompanied by a decrease in ablation performance. Coordinating the contradiction between lightweight and ablation resistance is the key to the development of thermal protection technology. Addressing the need for high‐performance insulation materials within solid rocket motors (SRMs) combustion chambers, we designed three multilayer composite structural insulation materials and studied their properties. The results show that among these constructed multilayer composites, the bilayer structure exhibited the lowest density at a mere 0.72 g/cm3, marking a 27% reduction compared to the basic structure. Remarkably, the bilayer configuration demonstrated superior ablation resistance, showcasing a 25% decrease in the line ablation rate in contrast to the basic structure after oxygen‐acetylene test. This achievement embodies the successful harmonization of lightweight properties with ablation resistance. Furthermore, based on the performance and microstructure of the char layer, a further analysis revealed the enhancement mechanism of ablative performance by the multilayer composite structure. It was found that the synergistic effect of the compact/porous structure of the char layer grants the bilayer structure thermal insulation material optimal ablative performance. This work provides strong support for improving the performance of SRMs.Highlights Insulation materials with multilayer composite structures are designed. The materials exhibit both lightweight and superior ablation resistance. Compact/porous char layers enhance material ablation performance.

An artifactual fibre overlap removal algorithm for micro-computed tomography image post-processing and 3D microstructure generation with graphics processing unit acceleration

A novel algorithm based on radial basis functions is proposed for the removal of artifactual fibre overlap within fibre structures extracted from micro-computed tomography (micro-CT) images of fibre reinforced polymer matrix composites. The proposed algorithm is highly efficient and excels in preserving the original fibre structures extracted from the micro-CT images. Besides, graphics processing unit (GPU) acceleration is applied to further enhance the efficiency of the fibre overlap removal process. Furthermore, the proposed algorithm is also modified for the generation of periodic 3D microstructures. For practical application, the proposed algorithm is implemented for both the artifactual fibre overlap removal within micro-CT images from an injection moulded part and the microstructure generation for 3D printed samples. The unidirectional elastic modulus of the resultant microstructures is computed via numerical simulations and shows a close match to the experimental measurements with relative errors less than 2%. Overall, the proposed algorithm significantly facilitates the reconstruction of micro-CT image-based numerical models and can also be easily repurposed to generate complex microstructures, which is of great value for the development of data-driven models for characterization and design of composite materials that demands large amounts of data on material microstructures.

A Review of the Biomimetic Structural Design of Sandwich Composite Materials.

Sandwich composites are widely used in engineering due to their excellent mechanical properties. Accordingly, the problem of interface bonding between their panels and core layers has always been a hot research topic. The emergence of biomimetic technology has enabled the integration of the structure and function of biological materials from living organisms or nature into the design of sandwich composites, greatly improving the interface bonding and overall performance of heterogeneous materials. In this paper, we review the most commonly used biomimetic structures and the fusion design of multi-biomimetic structures in the engineering field. They are analyzed with respect to their mechanical properties, and several biomimetic structures derived from abstraction in plants and animals are highlighted. Their structural advantages are further discussed specifically. Regarding the optimization of different interface combinations of multilayer composites, this paper explores the optimization of simulations and the contributions of molecular dynamics, machine learning, and other techniques used for optimization. Additionally, the latest molding methods for sandwich composites based on biomimetic structural design are introduced, and the materials applicable to different processes, as well as their advantages and disadvantages, are briefly analyzed. Our research results can help improve the mechanical properties of sandwich composites and promote the application of biomimetic structures in engineering.

Prediction of low-velocity impact responses for bio-inspired helicoidal laminates based on machine learning

The inherent capacity of natural protective systems to withstand impact loadings, attributed to their microscale helicoidal architectures, has garnered significant interest. Drawing inspiration from this mechanically robust design, this study aims to introduce the composite laminates with a helicoidal distribution and to accurately and efficiently predict their Low-Velocity Impact (LVI) responses. Initially, the Latin hypercube design (LHS) was employed to generate 500 samples representing various pitch angles. An experimentally verified finite element model was then established to capture the load-displacement curves and energy-time curves for these 500 samples. Subsequently, the Convolutional Neural Network (CNN) model was utilized to accurately predict the load-displacement curves and energy-time curves for bio-inspired helicoidal laminates across different pitch angles. The principal component analysis (PCA) was used to enhance the efficiency of learning the load-displacement and energy-time curves in a reduced dimensional space, and the SHapley Additive exPlanations (SHAP) method was employed to investigate the feature importance of pitch angle. Finally, the helicoidal laminate with the highest energy absorption for a given volume was obtained by the genetic algorithm (GA) combined with the CNN model. This optimized laminate demonstrates a remarkable 9.5 % improvement in energy absorption compared to the best-performing sample within the original data set. Furthermore, the "spiraling" delamination damage of the helicoidal laminates was studied, which indicates that the delamination with small pitch angle is more pronounced for that with large pitch angle. The proposed method offers significant advantages in terms of cost reduction and efficiency enhancement for predicting the LVI responses of helicoidal laminates, holding immense potential in structural design and optimization of composite materials.

Structure effect of ENPs on mechanical properties of amorphous CuCo alloys

Nanoparticles play an important role in the properties of metallic glasses (MGs) due to their diversified structures; however, their structure–property relationship is unclear. In this paper, three ex situ metallic glass matrix composites were assembled by three kinds of nanoparticles and Cu50Co50 MG obtained by rapid cooling, and their structural evolution under uniaxial compression is investigated by molecular dynamic simulation. It is found that the activated atoms always preferentially accumulate in the amorphous region near the embedded nanoparticles (ENPs). ENPs hinder the propagation of shear bands and lead to strain-hardening behavior. The fractal structures convert the HCP and tDh atoms into atoms of other structures to improve the anti-deformation ability, and the parallel-twin structure improves the anti-deformation ability through the mutual conversion of the FCC and HCP atoms. These findings provide a new idea for improving the mechanical properties of MGs. The change in the ENP structure provides theoretical support for the design of composite materials with specific requirements for structural evolution.

Biomimetic Aramid Nanofiber/β-FeOOH Composite Coating for Polypropylene Separators in Lithium-Sulfur Batteries.

Aramid nanofibers (ANFs), with attractive mechanical and thermal properties, have attracted much attention as key building units for the design of high-performance composite materials. Although great progress has been made, the potential of ANFs as fibrous protein mimetics for controlling the growth of inorganic materials has not been fully revealed, which is critical for avoiding phase separation associated with typical solution blending. In this work, we show that ANFs could template the oriented growth of β-FeOOH nanowhiskers, which enables the synthesis of ANFs/β-FeOOH hybrids as composite coatings for polypropylene (PP) separators in Li-S batteries. The modified PP separator exhibits enhanced mechanical properties, heightened thermal performance, optimized electrolyte wettability, and improved ion conductivity, leading to superior electrochemical properties, including high initial specific capacity, better rate capability, and long cycling stability, which are superior to those of the commercial PP separators. Importantly, the addition of β-FeOOH to ANFs could further contribute to the suppression of lithium polysulfide shuttling by chemical immobilization, inhibition of the growth of lithium dendrites because of the intrinsic high modulus and hardness, and promotion of reaction dynamics due to the catalytic effect. We believe that our work may provide a potent biomimetic pathway for the development of advanced battery separators based on ANFs.

Systematization of the application of polymer composite materials in the design of bridge structures

Background. This study systematizes the principles of using polymer composite materials in bridge structure design, outlining the fundamental principles for calculating load-bearing structures of bridge spans featuring these materials. Aim. The goal is to enhance the strength and durability of bridge spans during construction and maintenance, while optimizing costs through the use of polymer composite materials. Materials and Methods. The research employs a modern approach to bridge structure design, utilizing mathematical statistics for experimental data analysis and numerical methods for calculating bridge structures using nonlinear deformation models of anisotropic materials. Results. Developed principles for designing bridge spans with polymer composite elements include methods for strengthening and reinforcing concrete bridge structures. These methods account for operational factors such as long-term constant and temporary loads, low and elevated temperatures, as well as methods for designing all-composite spans pedestrian and road bridges Conclusion. The principles of designing bridge spans with elements made of polymer composite materials have been introduced into the practice of transport construction in the Russian Federation. The technical and economic efficiency of using polymer composite materials in bridge structures of transport infrastructure has been confirmed.