Design Of Composite Materials Research Articles

Methods and tools for assessing the accuracy of composite property models

Property modeling is essential for optimal application and efficient design of new composite materials. Although numerous models of composite properties are available in the literature, there is a lack of rigorous validation of these models. This paper introduces a freely distributed collection of experimental data on the electrical and dielectric properties of composites and an open-source program package for modeling and testing composite property models. The software provides a quantitative estimation of prediction accuracy, making it a valuable tool for assessing the quality of a composite model. The paper demonstrates the use of the proposed tools to estimate two-phase models of composite electrical conductivity that account for the filler shape. The results of this test showed that the examined models failed to simulate the shape of the filler. Also, the article gives an example of the comparison of three-phase models of relative permittivity of composites with fitting parameters. In addition, the study presents the analysis of errors in the approximation of experimental data by the model, as well as recommendations on methods and selection of criteria for evaluating the quality of models.

Interface structure and tensile failure behaviour of novel SiCf/Ti–Ti2AlNb hybrid laminated composite material

Inspired by the microstructures of shells, SiC fibers (SiCf) are introduced into Ti layers, creating hybrid layers of SiCf/Ti, which are combined with Ti2AlNb foils to prepare multilayer SiCf/Ti–Ti2AlNb hybrids in a hot-pressed sintering instrument. The solid-phase bonding interface, mainly including the α+β biphasic structures and B2-rich phases, guarantees an ideal interface connection between the SiCf/Ti and Ti2AlNb layers after the sintering. Herein, the SiC fibers-made SiCf/Ti–Ti2AlNb presents a higher tensile strength and elasticity modulus on the tensile instrument of Model No. Byes (2010), compared with Ti/Ti2AlNb. During the tensile process, the brittle fractures of SiCf first occur, and the loads are transferred to the bonding interface of the Ti2AlNb and Ti layers, generating the crack propagation and resulting in SiCf/Ti–Ti2AlNb fracture. This is mainly because the crack is extended in succession to the bonding interface that is composed of brittle phases such as O and α2, as well as ductile phases such as α, β and B2. This produces the ductile and brittle ruptures at the bonding interface, forming the ductile-brittle mixture fractures at the SiCf/Ti and Ti2AlNb interfaces. In the case of vertical fractures related to the fiber length, brittle fractures are observed on the SiC fibers, which produce high forces that affect their bonding interfaces, resulting in axial interstices and transverse fractures. These obtained results demonstrate a novel method for structural design and fabrication of the innovative composite materials.

Enhanced Reverse-Engineering Method for Accurately Predicting Lamina Properties in Laminated Composites via Combined Static and Dynamic Finite Element Simulations

This study aims to ascertain the material characteristics that are intrinsic to the prepreg layer within a laminated composite structure. The elastic modulus of the lamina, a primary determinant of composite structural behavior, is the focal point of this analysis. This parameter has been assessed by employing reverse-engineering techniques on a composite composed of sequentially stacked prepregs. The investigation entailed simulating the behavior of the composite under static loads and conducting modal analyses to reflect both static and dynamic conditions. The findings indicate that the elastic modulus values derived from combined tensile and modal analysis simulations exhibit superior accuracy compared to those obtained through tensile simulation alone. Specifically, the maximum prediction error for E1 (the tensile-direction elastic modulus of one lamina sheet) decreased from 1.17% to 0.28%, and that of E2 (the transverse-direction elastic modulus of one lamina sheet) decreased from 12.01% to 7.30%. Further simulations incorporating fabrication error variances underscored the critical nature of precise E2 analysis. The proposed methodology evidenced a more accurate assessment of E2, underscoring its potential to enhance the reverse-engineering process in composite material design.

Pd and carbon quantum dots co-decorated TiO2 nanosheets for enhanced photocatalytic H2 production and reaction mechanism

TiO2-based composites are promising photocatalysts for efficient generation of the clean energy, H2, from water splitting. Herein, series of Pd nanoparticles and carbon quantum dots (CQDs) co-decorated TiO2 nanosheets (NSs), Pd-CQDs/TiO2, were designed by overall considering taking advantages of the three components: highly active TiO2 NSs, highly conductive CQDs and electron sink of Pd. Series of photocatalytic experiments were performed and the photocatalytic reaction mechanism was explored. The Pd-0.5CQDs/TiO2 exhibited an excellent photocatalytic hydrogen evolution rate (HER), which is 901.5, 41.8 and 1.7 times higher than those of the bare TiO2, 0.5CQDs/TiO2 and Pd/TiO2, respectively. The synergistic effect of the CQDs and Pd was found responsible for the enhanced photocatalytic activity of the Pd-0.5CQDs/TiO2. Besides, the CQDs was found facilitating complete conversion of Pd2+ to metallic Pd on the surface of TiO2 NSs, which may offer a new thought for design of other composite materials.

Architectural control over morphologies of bottlebrush block copolymer superstructures

The morphology of superstructures formed by bottlebrush block copolymers in the melt can be tuned by changing the side chain length or/and their grafting density at constant volume fractions of the blocks. This feature enables fabrication of microphase separated bulk structures and mesoporous materials thereof with spherical or cylindrical domains (precursors of the mesopores), with high porosity unattainable for materials produced from conventional linear block copolymers. These paradigms are proven by DPD simulations that allow constructing morphological phase diagrams of the melt of block copolymers comprising one linear and one bottlebrush block and comparing the simulation results to the predictions of the mean field analytical theory. While the binodal lines separating the stability regions of spherical and cylindrical domains predicted by the theory perfectly match the simulation results, the simulation indicates appearance of a gyroid phase around the theoretical binodal separating the stability ranges of cylinders and lamellae. The results of our work provide guidelines for macromolecular design of novel composite and mesoporous materials with a wide spectrum of potential applications.

Laser speckle-based estimation of surface condition for designing quieter material

Laser speckle is a non-contact, non-interfering, non-destructive, rapid and controllable technique with a large area of coverage that has attracted much attention for surface analysis of materials. The emergence of different natural cellulosic materials as potential candidates for the replacement of synthetic ones is promising, but their sustainability from the point of view of material design is still in question. Machining of the surface of cellulosic components for making sound-dampening materials has a critical effect on determining their surface condition. Laser speckle is an emerging tool for surface analysis of a variety of materials, and it has important applications in material design and analysis. As a cutting-edge research tool, ultrasonic wave technology has maintained a significant contribution to the design and structural monitoring of composite materials. The present work uses date palm leaf fibers for composite reinforcement. The sound-dampening properties, such as sound absorption and transmission, were analyzed on the basis of surface roughness observed with the laser speckle technique and modified by ultrasonically blended surfactants. The surface roughness of the synthesized material was found to increase with sonication time with an R 2 value of 0.944 and observed fluctuation in roughness data on the surface of the material. The sound absorption coefficient is 0.98 with a transmission loss of 60 dB, for which the material is classified as an ASTM E1050 Class A acoustic material. Further, the method of laser speckle-based roughness estimation is found to be potential tool for the design of any type of quieter material.

Influence of water absorption track and pre‐drying treatment on the long‐term hydrothermal aging behavior of recycled jute fabric‐reinforced composites

AbstractCorrosion resistance and durability are always considered in the safety design of composite materials. In this study, recycled jute woven fabrics from coffee bags were used to fabricate jute/unsaturated polyester composites. The effect of water absorption and pre‐drying treatment on the long‐term hydrothermal aging behavior of the prepared composites, as well as the aging mechanism, was discussed. The hydrothermal aging test was performed at a fixed temperature of 80°C for specified conditioning times of 24, 120, 240, 480, and 720 h. Weight gain and weight loss values were recorded and compared. The mechanical properties were evaluated using a three‐point bending test and observations of the fracture area. The results showed similar water uptake and flexural behaviors between the composites with different pre‐drying treatments, especially after long‐term hydrothermal aging. It was also found that the moisture diffusion of the composite followed a Fickian process, and the flexural properties of the bending specimens at every position reduced with the aging time and initially decreased rapidly during the first 24 h of aging. In particular, the reduction rate in flexural properties generally followed the sequence of NO.1 > NO.2 > NO.6 > NO.5. Additionally, the aging mechanism study revealed three steps for the composites during the water absorption process. The inclusion of jute fiber as a composite material in this research provides insight into the water‐absorption mechanism of jute fabric‐reinforced polymer composite (JFRP).Highlights Recycled jute fabric‐reinforced composites were produced using jute fabrics obtained from recycled coffee bags. The effect of the water absorption track and pre‐drying treatment on the long‐term hydrothermal aging behavior of recycled jute fiber‐reinforced composite and its aging mechanism is discussed. The clarification of the aging mechanism indicates that there are three steps involved in the water absorption process. Considering jute fiber as a composite could help explain the water‐absorbing mechanism of JFRP.

Machine learning-based assessment of hygrothermal aging performance in CFRP-aluminum alloy adhesive bonded structures

ABSTRACT Adhesive bonding is an effective technique for connecting fiber reinforced composites (FRPs) and plays a crucial role in determining load transfer capability and overall structural safety. However, long-term exposure to temperature and moisture can degrade adhesive joints, highlighting the significant importance of accurately predicting their durability when designing reliable adhesive structures. This study aims to address the industry’s demand and academic interest by proposing a convenient and accurate prediction method to evaluate the durability of adhesive structures subject to complex stresses. Laboratory accelerated aging experiments were conducted on butt joints (experiencing pure normal stress) and shear joints (experiencing pure shear stress). Quasi-static tensile tests and adhesive FTIR tests were performed to establish a dataset of adhesive functional group absorbance and failure strength under single stress conditions. To compare and assess the predictive performance of different models for aging behaviors, Artificial Neural Network (ANN), Support Vector Regression (SVR) and Random Forest (RF) models were selected. The model hyperparameters were further optimized using the Genetic Algorithm (GA). The results demonstrated that the ANN model exhibited superior correlation and accuracy compared to the SVR, and RF. The characteristic importance analysis revealed that the hydrolysis and post-curing of adhesives were the primary factors affecting joint performance under hygrothermal environments. By incorporating environmental degradation factors and defining initial failure criteria, the CZM constitutive model was modified and a predictive method was established for assessing the hygrothermal aging behavior of CFRP/aluminum alloy bonding structures. This method effectively eliminates the effect the intricate aging process (e.g. aging time, aging conditions) and establishes a direct correlation between the molecular structure of adhesive and the macroscopic mechanical properties of the bonded joint, which serves as a valuable reference and guidance for the safety design of automotive composite material bonding structures throughout their entire lifespan.

Effect of stitch density on the damage inhibition and compression strength after high-velocity impact of UHMWPE fiber composites

This paper investigates the effect of stitch density on the high-velocity impact damage inhibition and CAI (compression after impact) strength of UHMWPE (Ultra-High Molecular Weight Polyethylene) fiber composites. The damage response and compression behavior after impact were quantified and analyzed using CT scanning and DIC (Digital Image Correlation) techniques. The findings reveal that the delamination area of the composite plate with the stitch space of 1 cm reduces by 49.14 % compared to the unstitched sample, and exhibits a 73.05 % higher compressive load than the plate with a 4 cm stitch space. Notably, the 4 cm stitch composite plates demonstrate a significant advantage in energy absorption. However, the sparse stitch structure destroys the original structure inside the composite, resulting in a degradation of CAI performance. The study provides guidance for the practical design of composite materials with enhanced energy absorption and damage resistance.

Material Design of Citric Acid-Modified Cellulose Composite Polymeric Materials with Both Tough and Sustainable Enhancement by Multiple Noncovalent Bonds

Material Design of Citric Acid-Modified Cellulose Composite Polymeric Materials with Both Tough and Sustainable Enhancement by Multiple Noncovalent Bonds

Orientation optimization via topological derivatives in combination with multi-material topology optimization based on extended level set method

This paper provides an orientation angle optimization method for the design of fiber-reinforced composite materials using topology optimization. The orientation angle optimization is based on a topological derivative, which measures the sensitivity of an objective function with respect to a topological change of anisotropic materials. The sensitivity is incorporated into a new gradient-based optimization algorithm. This method improves our ability to obtain better optimal candidates. We provide some numerical examples and verify the effectiveness of the proposed method.

Promoting Electromagnetic Wave Absorption Performance by Integrating MoS2@Gd2O3/MXene Multiple Hetero-Interfaces in Wood-Derived Carbon Aerogels.

Multi-component composite materials with a magnetic-dielectric synergistic effect exhibit satisfactory electromagnetic wave absorption performance. However, the effective construction of the structure for these multi-component materials to fully exploit the advantages of each component remains a challenge. Inspired by natural biomass, this study utilizes wood as the raw material and successfully prepares high-performance MoS2@Gd2O3/Mxene loaded porous carbon aerogel (MGMCA) composite material through a one-pot hydrothermal method and carbonization treatment process. With a delicate structural design, the MGMCA is endowed with abundant heterogeneous interface structures, favorable impedance matching characteristics, and a magnetic-dielectric synergistic system, thus demonstrating multiple electromagnetic wave loss mechanisms. Benefiting from these advantages, the obtained MGMCA exhibits outstanding electromagnetic wave absorption performance, with a minimum reflection loss of -57.5dB at an ultra-thin thickness of only 1.9mm. This research proposes a reliable strategy for the design of multi-component composite materials, providing valuable insight for the design of biomass-based materials as electromagnetic wave absorbers.

Wave analysis in porous thermoelastic plate with microtemperature

AbstractIn the current study, wave analysis in porous thermoelastic plates with microtemperature subject to insulated or isothermal boundaries is the main focus. The governing equations, after expressing for the two‐dimensional case, are converted into nondimensional quantities. For further simplification, potential functions have been used. The normal mode analysis technique is applied to solve the problem. This technique is an influential methodology that furnishes suitable solutions with no presumed limitations. For stress‐free insulated, or isothermal boundaries, the frequency equations for symmetric and skew‐symmetric modes of wave propagation are derived. The attributes of waves (phase velocity, attenuation coefficient, specific loss, and penetration depth) are computed numerically and presented graphically to show the impacts of porosity and microtemperature. Particular cases of porous thermoelastic plates and thermoelastic plates with microtemperatures are presented. The present problem provides a theoretical foundation for the design and development of new composite materials and surface acoustic devices.

Mechanistic exploration of Co doping in optimizing the electrochemical performance of 2H-MoS2/N-doped carbon anode for potassium-ion battery

The 2H-MoS2/nitrogen-doped carbon (2H-MoS2/NC) composite is a promising anode material for potassium-ion batteries (PIBs). Various transition metal doping has been adopted to optimize the poor intrinsic electronic conductivity and lack of active sites in the intralayer of 2H-MoS2. However, its optimization mechanisms have not been well probed. In this paper, using Cobalt (Co) as an example, we aim to investigate the influence of transition metal doping on the electronic and mechanical properties and electrochemical performance of 2H-MoS2/NC via first-principles calculation. Co doping is found to be effective in improving the electronic conductivity and the areas of active sites on different positions (C surface, interface, and MoS2 surface) of 2H-MoS2/NC. The increased active sites can optimize K adsorption and diffusion capability/processes, where general smaller K adsorption energies and diffusion energy barriers are found after Co doping. This helps improve the rate performance. Especially, the pyridinic N (pyN), pyrrolic N (prN), and graphitic N (grN) are first unveiled to respectively work best in K kinetic adsorption, diffusion, and interfacial stability. These findings are instructive to experimental design of high rate 2H-MoS2/NC electrode materials. The roles of different N types provide new ideas for optimal design of other functional composite materials.

Organic–inorganic interface enhancement for boosting mechanical and tribological performances of carbon fiber reinforced composites

AbstractThe limitation in the poor interface would severely affect the further development and application of carbon fiber reinforced composites (CFRP). Unique organic–inorganic hybrid architectures of MOF‐5‐NH2 and carboxymethyl cellulose (CMC) were established on the fiber/matrix interphase for promoting mechanical and tribological performances of the composites. The existence of above interfacial reinforced structure was in favor of generating abundant micromechanical interaction sites for enhancing mechanical interlocking. Meanwhile, high‐density chemical crosslinking networks played a positive role in elevating interfacial adhesion, further relieving stress concentration and hindering crack propagation. The tensile strength of CFRP‐2, CFRP‐3, CFRP‐4, and CFRP‐5 exhibited a significant rising of 27.18%, 30.64%, 27.75%, and 36.88%, respectively. The friction coefficient of MOF‐5‐NH2/CMC modified sample increased from 0.0953 to 0.1219, while the drop in the wear rate of the composites achieved 68.51%. This work provides an effective method for achieving the structure–function integrated design of composite materials according to the organic–inorganic interface enhancement of MOF‐5‐NH2/CMC.

Sr(NH2SO3)(NO3)·H2O: An Ultraviolet Nonlinear Optical Material Exhibiting Strong Second-Harmonic Generation Response and Sufficient Birefringence.

Second-harmonic generation (SHG) response and birefringence stand as fundamental optical properties for nonlinear optical (NLO) materials. Up to now, engineering a strong SHG response and substantial birefringence in the sulfamate system has proven to be exceedingly challenging. A novel noncentrosymmetric compound, Sr(NH2SO3)(NO3)·H2O, has been meticulously designed by introducing the (NO3)- group characterized by significant polarizability anisotropy and hyperpolarizability into the polar non-π-conjugated (NH2SO3)- system. This compound exhibits a robust SHG response (5.2 × KDP), ample birefringence (0.077 at 546.1 nm), and a short ultraviolet (UV) absorption edge (290 nm). The linear and nonlinear optical properties can be attributed to the (NO3)- group and the (NH2SO3)- group. This study presents an effective approach that contributes to the design of more composite anionic UV NLO materials with excellent and balanced optical properties.

RESEARCH AND ANALYSIS OF THE PROPERTIES OF COMPOSITE MATERIALS. DEFINITION AND CLASSIFICATION OF COMPOSITE MATERIALS

Unlike conventional materials, composites have become a suitable form for a range of current applications in industry, hospital and sports. This is combined with their remarkable physical, thermal, galvanic and mechanical properties, as well as, in addition, their low weight and investment cost in the given cases. This review article attempts to provide a general concept of composite materials, definition and classification of composite materials, most commonly polymer matrix composites and metal matrix composites. Polypropylene polyurethane and aluminum alloy were selected as matrices for this extract given their attractive properties and their use in various applications. All kinds of research are devoted to a variety of building materials, material processing and various properties. The determination of mechanical data appears to be a significant iterative process in the development and design of composite materials and their components. With regard to the mechanical properties of composite materials, this article highlights some of the uncertainties and limitations that affect the evaluation of mechanical properties, ranging from material constituents, industrial process, test characteristics and environmental conditions.

Mo2N quantum dots decorating N-doped carbon nanosheets for kinetics-enhanced Li-S batteries

Lithium-sulfur (Li-S) batteries face two main challenges, which are the severe shuttle effect of lithium polysulfides (LiPSs) and the slow redox kinetics of LiPSs. Herein, monodispersed Mo2N quantum dots decorating N-doped carbon nanosheets (Mo2N@NCNS) are rationally engineered via a simple and cost-effective method and used as an effective host for sulfur in high-performance Li-S batteries. Mo2N@NCNS presents enhanced intrinsic conductivity, superior catalytic capability, and improved LiPSs redox kinetics. The 3D N-doped carbon nanosheet networks endowed with abundant catalytic sites can heighten physically confined and chemically adsorptive LiPSs by strongly polar-polar interactions, further regulating the disordered motion of LiPSs. In the meanwhile, the highly dispersed Mo2N quantum dots with powerful adsorptive-catalytic properties anchor the soluble LiPSs and facilitate high-efficiency diffusion-conversion kinetics for the nucleation and deposition of Li2S2/Li2S, thus promoting the complete utilization of sulfur and the overall enhancement of electrochemical performance. Owing to these fascinating features, the Mo2N@NCNS-based sulfur cathodes demonstrate substantial enhancement in electrochemical performance, including remarkable capacity performance (1221 mAh g−1 at 0.2 C) and exceptional cyclability over 800 cycles at 2 C with a minimal decay rate (0.03 % per cycle). This work highlights the great potential of rational design of advanced composite materials for promoting the practical viability of Li-S batteries in energy storage systems.

Preparation of microstructure controllable Al/WO3/F2603 MICs by droplet microfluidic technology to improve combustion performance

The microstructure of metastable intermolecular composites (MICs) is crucial for their energy release and combustion performance. In this paper, Al/WO3/F2603 composites with controllable microstructure were prepared by droplet microfluidic technology. The microstructure control method of composite materials based on droplet microfluidic technology (DMT) was studied. Particles with controllable size, shape, composition, structure and function were prepared by droplet template, and the formation mechanism of particle microstructure was introduced. The Al/W/F-2 composites with high-quality spherical encapsulation have excellent flow properties and wettability. The ignition delay, combustion time and pressure output of the composites were monitored by a combustion and pressure test system. Compared with the physically mixed samples, the Al/W/F-x composites prepared by DMT have shorter ignition delay, shorter combustion duration, and higher pressurization rate. The analysis of combustion products showed that the encapsulated Al/W/F-x composites reduced the sintering and agglomeration of reactants and promoted the combustion efficiency. The results show that the characteristic structure design of the composite material can establish the interface synergy, enhance the thermal mass transfer between the components, and thus reduce the ignition delay and improve the combustion performance. DMT can realize the controllable preparation of composite microstructure, which provides a reference for the design and preparation of other composite materials.

Design and fabrication of bio-based functional composite materials with antibacterial, antioxidant, and improved mechanical properties based on poly (butylene adipate-co-terephthalate) (PBAT) for food packaging

The PBAT/epoxy chain extender (ADR-4468) film, with its competitive pricing, excellent biodegradability, and outstanding mechanical properties, stands out. Through experimental design, quercetin (QR) with antibacterial and antioxidant properties was effectively grafted onto the epoxy chain extender (ADR-4468), resulting in the successful synthesis of the functional modifier A-QR. PBAT composite films containing different weight percentages (0.2, 0.4, 0.6, 0.8, and 1% w/w) of A-QR were prepared using extrusion blow molding technology. QR and ADR are chemically bonded together, forming a strong and tightly knit composite. The composites exhibit excellent composite effects and outperform single-component blends, reducing A-QR migration, improving mechanical properties, and enhancing the barrier properties of the composite film. Structural, mechanical, and water barrier properties, antibacterial and antioxidant properties, as well as freshness preservation effects of the film, were analyzed. A-QR and PBAT formed a cross-linked network structure through chain extension reactions. Tensile strength increased from 19.7 MPa to 37.9 MPa, representing a 92.4% improvement. Antioxidant activity reached up to 65%. It exhibited excellent antibacterial activity against Staphylococcus aureus and Escherichia coli. The maximum total migration was only 0.7 mg/dm2, significantly below the specified overall migration limit (OML). PBAT/A-QR films successfully extended the shelf life of bananas, strawberries, apples, and oyster mushrooms due to their excellent antioxidant, antibacterial, and water barrier properties.