Structure Of Composite Materials Research Articles

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.

Inductive Frequency-Coded Sensor for Non-Destructive Structural Strain Monitoring of Composite Materials

Structural composite materials have gained significant appeal because of their ability to be customized for specific mechanical qualities for various applications, including avionics, wind turbines, transportation, and medical equipment. Therefore, there is a growing demand for effective and non-invasive structural health monitoring (SHM) devices to supervise the integrity of materials. This work introduces a novel sensor design, consisting of three spiral resonators optimized to operate at distinct frequencies and excited by a feeding strip line, capable of performing non-destructive structural strain monitoring via frequency coding. The initial discussion focuses on the analytical modeling of the sensor, which is based on a circuital approach. A numerical test case is developed to operate across the frequency range of 100 to 400 MHz, selected to achieve a balance between penetration depth and the sensitivity of the system. The encouraging findings from electromagnetic full-wave simulations have been confirmed by experimental measurements conducted on printed circuit board (PCB) prototypes embedded in a fiberglass-based composite sample. The sensor shows exceptional sensitivity and cost-effectiveness, and may be easily integrated into composite layers due to its minimal cabling requirements and extremely small profile. The particular frequency-coded configuration enables the suggested sensor to accurately detect and distinguish various structural deformations based on their severity and location.

The acoustic Galton board

Phononic crystals are a class of materials with periodic structures that influence the propagation characteristics of acoustic waves through periodically arranged structural units. Here, we have developed the acoustic Galton board (AGB), a groundbreaking apparatus that serves as a cost-effective and user-friendly tool for demonstrating phononic crystal properties such as band gaps, Bragg scattering, and local resonance. The device comprises an elastic wave signal generator, an enhanced Galton board featuring a sophisticated pillar-nail array, and a signal receiver. The experimental results we have obtained demonstrate the significant impact of the AGB on elastic wave dispersion, effectively creating bandgaps that impede wave transmission within specific frequency ranges while allowing unhindered propagation in others. Furthermore, the AGB can simulate phononic crystals using both the Bragg scattering mechanism, achieved through the design of periodic rigid pillar-nail arrays, and the locally resonant mechanism, facilitated by the design of pillar-nail arrays with composite material structures. Additionally, the AGB can extend its applications to serve as a simulation tool for elastic metamaterials.

The Role of Methods for Applying Cucurbit[6]uril to Hydroxyapatite for the Morphological Tuning of Its Surface in the Process of Obtaining Composite Materials

In this work, composite materials were obtained for the first time using various methods and the dependences of the resulting surface morphologies were investigated. This involves modifying the surface with cucurbit[n]urils, which are highly promising macrocyclic compounds. The process includes applying cucurbit[6]uril to the hydroxyapatite surface in water using different modification techniques. The first method involved precipitating a dispersion of CB[6] in undissolved form in water. The second method involved using fully dissolved CB[6] in deionized water, after which the composite materials were dried to constant weight. The third method involved several steps: first, CB[6] was dissolved in deionized water, then, upon heating, a dispersion of CB[6] was formed on the surface of HA. The fourth method involved using ultrasonic treatment. All four methods yielded materials with different surface morphologies, which were studied and characterized using techniques such as infrared (IR) spectroscopy and scanning electron microscopy (SEM). Based on these results, it is possible to vary the properties and surface morphology of the obtained materials. Depending on the method of applying CB[6] to the surface and inside the HA scaffold, it is possible to adjust the composition and structure of the target composite materials. The methods for applying CB[6] to the hydroxyapatite surface enhance its versatility and compatibility with the body’s environment, which is crucial for developing new functional composite materials. This includes leveraging supramolecular systems based on the CB[n] family. The obtained results can be used to model the processes of obtaining biocomposite materials, as well as to predict the properties of future materials with biological activity.

Electromagnetic Interference Shielding Films: Structure Design and Prospects.

The popularity of portable and wearable flexible electronic devices, coupled with the rapid advancements in military field, requires electromagnetic interference (EMI) shielding materials with lightweight, thin, and flexible characteristics, which are incomparable for traditional EMI shielding materials. The film materials can fulfill the above requirements, making them among the most promising EMI shielding materials for next-generation electronic devices. Meticulously controlling structure of composite film materials while optimizing the electromagnetic parameters of the constructed components can effectively dissipate and transform electromagnetic wave energy. Herein, the review systematically outlines high-performance EMI shielding composite films through structural design strategies, including homogeneous structure, layered structure, and porous structure. The attenuation mechanism of EMI shielding materials and the evaluation (Schelkunoff theory and calculation theory) of EMI shielding performance are introduced in detail. Moreover, the effect of structure attributes and electromagnetic properties of composite films on the EMI shielding performance is analyzed, while summarizing design criteria and elucidating the relevant EMI shielding mechanism. Finally, the future challenges and potential application prospects of EMI shielding composite films are prospected. This review provides crucial guidance for the construction of advanced EMI shielding films tailored for highly customized and personalized electronic devices in the future.

Comparative analysis of the heavy-weight floor impact noises using different types of EVA resilient materials

The present study aims to improve the floor impact noises using various shapes of EVA resilient materials in composite floor structures. In order to this, three different types of EVA resilient materials were used including flat plate, deck plate type and cavity type of EVA boards. All the composite structure consisted of PP panel, PET and EVA resilient materials with a total depth from 30mm to 40mm. Total of 9 specimens were made for floor impact sound measurements. All the floor impact sound measurements were done at the recognized testing authority using bang machine. The values of L'I,Fmax,AW were deduced from every measurements. As a result, among the various types EVA resilient materials, most high performances were drawn when cavity type of EVA resilient material was used. It was shown that the average L'I,Fmax,AW value of cavity type was 46dB while 47dB for deck plate type, 48dB for flat plate were measured in average. It can be recognized that the good performance of cavity type EVA materials is caused by the both air layer gap beneath EVA board and air cavity inside the EVA board as well as the low dynamic elastic modulus of EVA.

Experimental study on damage of steel fiber reinforced concrete- and wood-filled GFRP tubes under axial compression

In order to reduce the self-weight of concrete structures and improve its corrosion resistance, it is an effective way to fill GFRP tubes with wood columns instead of part of concrete. However, concrete structures are prone to cracks, which will reduce the bearing capacity of the structure and affect the safety and applicability of the structure. Incorporating the steel fibers (SF) in concrete seems to be an excellent solution to limit crack propagation and improve the ductility of concrete structures. Based on the premise, in this paper, a new type of structure composite material of steel fiber reinforced concrete- and wood-filled GFRP tubes was developed. The mechanical properties, damage evolution process and crack fractal characteristics of steel fiber reinforced concrete- and wood-filled GFRP tubes under axial compression with different SF volume fractions (0 %, 1 %, 1.5 % and 2 %) were studied by acoustic emission (AE) technology. The finite element method (FEM) was established to simulate the test work and expand the analysis. The results showed that the bearing capacity and ductility of the specimens increased first and then decrease with the increase of SF content, and the specimens with 1.5 % volume fraction of SF showed the best mechanical properties. According to the characteristics of AE ringing counts, the damage process of the specimen was described by three marker events, which were concrete cracking, wood cracking and GFRP tube fracture. The incorporation of SF increased the intensity of AE signal and the proportion of shear cracks, and reduced the damage scale. The fractal dimension of concrete surface cracks had a good correlation with the degree of local damage and the complexity of crack propagation. The damage evolution model based on AE cumulative events and stress obeyed the two-parameter Weibull distribution. The incorporation of SF reduced the degree of damage, and the parameter m had a negative correlation with brittleness. In addition, the damage process of the specimens revealed by the FEM matched well with the experimental results. Additionally, the incorporation of SF made the stress distribution of each part of the specimen more uniform and avoided the phenomenon of stress concentration.

Mechanically durable plant-based composite surface towards enhanced antifouling properties

The biofouling adhering to underwater facilities has a negative impact on the environment, energy, and economic development. However, conventional anti-adhesion organic silicon and organic fluorine materials often have poor adhesion properties and mechanical stability when combined with substrates. This work presents a novel strategy for preparing composite antifouling coatings that low surface energy plant-based carnauba wax (CW) covering through rough substrates and chemically bond with flexible polydimethylsiloxane (PDMS) oligomers or polymers. The CW coating adheres strongly to the substrate owing to the mobility of the liquated CW, which flows into the micro-nano structure of the substrate and solidifies on the solid surface. The polymerization reaction of (PDMS) oligomers compounded the coating, thereby creating a composite coating with superior lubricating and antifouling properties. This distinctive bonding process imbued the coating with exceptional characteristics, including remarkable mechanical stability in destructive tests as well as an impressive ability to repel fouling, such as protein attachment, bacterial adhesion, diatom deposition, and biofilm formation. This work systematically investigated the impact of the composition and structure of composite materials on their mechanical stability and resistance to fouling, and developed high-performance antifouling coatings in the real world.

Being thin-skinned can still reduce damage from dynamic puncture.

The integumentary system in animals serves as an important line of defence against physiological and mechanical external forces. Over time, integuments have evolved layered structures (scales, cuticle and skin) with high toughness and strength to resist damage and prevent wound expansion. While previous studies have examined their defensive performance under low-rate conditions, the failure response and damage resistance of these thin layers under dynamic biological puncture remain underexplored. Here, we utilize a novel experimental framework to investigate the mechanics of dynamic puncture in both bilayer structures of synthetic tissue-mimicking composite materials and natural skin tissues. Our findings reveal the remarkable efficiency of a thin outer skin layer in reducing the overall extent of dynamic puncture damage. This enhanced damage resistance is governed by interlayer properties through puncture energetics and diminishes in strength at higher puncture rates due to rate-dependent effects in silicone tissue simulants. In addition, natural skin tissues exhibit unique material properties and failure behaviours, leading to superior damage reduction capability compared with synthetic counterparts. These findings contribute to a deeper understanding of the inherent biomechanical complexity of biological puncture systems with layered composite material structures. They lay the groundwork for future comparative studies and bio-inspired applications.

The Influence of Aluminosilicate Cenospheres on the Structure and Properties of Elastomeric Composite Materials Based on Ethylene–Propylene–Diene Elastomers

The Influence of Aluminosilicate Cenospheres on the Structure and Properties of Elastomeric Composite Materials Based on Ethylene–Propylene–Diene Elastomers

Black phosphorus modified wearable textile with excellent flame retardancy for personal thermal management and motion detection

A sandwich structure composite phase change textile material (CPCTM) was prepared by electrospinning. In the top and bottom layers, black phosphorus nanosheets (BPNs) was compounded into polyacrylonitrile (PAN). In the middle layer, the phase change thermal energy storage material polyethylene glycol (PEG) was well encapsulated by polyvinyl alcohol (PVA). By designing multilayer structure, the CPCTM exhibited excellent intensity with the tensile strength 62.65MPa and the elongation at break 1176%. The melting temperature and the crystallization temperature of CPCTM were 54.36 ℃ and 31.43 ℃ which were lower than pure PEG (55.87 ℃ and 35.55 ℃). The lower melting and crystallization temperature facilitated the storage of heat in CPCTM for body thermal management. Compared with that of pure PAN, the total heat release and total smoke production of the PAN@BP were respectively descended by 33.05% and 80.43%. During combustion, transfer of combustible gases and heat were hindered due to the formation of the expanded char layer by the BPNs. Meanwhile, the CPCTM showed excellent flexibility and ability of motion detection, which had broad application prospects in the fields of wearable electronic devices.

Fabricating sandwich composite tubes using a new thermal expansion technique: Materials preparation and energy absorption characteristics

The extensive application of hollow composite structures in engineering increasingly demands innovations in highly efficient and economical manufacturing processes as well as materials to achieve lightweighting and enhance mechanical performance. To address the limitations of traditional molding processes in fabricating hollow composite structures with intricate geometries, this study proposes a novel thermal expansion molding technique. This method eliminates the need to remove the mandrel after molding, making it exceptionally suitable for the molding of foam sandwich composite structures. Leveraging this new technique, lightweight sandwich composite tubes filled with polymethacrylimide (PMI) foam and thermal expansion foam were successfully fabricated. Considering the importance of crashworthiness for automotive applications, detailed experimental studies were conducted to investigate the crushing performance of the sandwich composite tubes prepared using this technology. Experimental results reveal that the synergistic effect between the multi-component materials within the sandwich composite tubes confers surprising energy absorption characteristics and crushing stability to the structure. The sandwich composite tubes prepared by this innovative thermal expansion process exhibit promising prospects as crashworthy structures for automotive lightweighting applications, and this method provides critical inspiration for the fabrication of composite structures with complex shapes.

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.

High sensitivity fiber optic SPR sensor for selenium ion concentration detection

Balance of selenium content is of great significance to human health, and there is a need for rapid and sensitive detection of selenium ion concentrations in the human body and food. This article proposes a highly sensitive fiber surface plasmon resonance (SPR) sensor for selenium ion concentration detection. By fabricating a fiber U-shaped ring composite structure and modifying Cu3VSe4 material, the sensitivity of the fiber SPR sensor is improved to 6826.82 nm/RIU. Using 2,4-diamino-6phenyl-1,3,5-triazine to modify the surface of the sensor to achieve specific detection of selenium ion concentration. The experiment results indicate that the detection sensitivity of the sensor is 1.858 nm/(lg(pg/ml)) with range of 100 pg/ml to 1 μg/ml, and the LOD is 124.06 pg/ml. The highly sensitive SPR sensor proposed in this article, without labeling, can achieve high sensitivity and rapid detection of selenium ions, providing a new approach for trace element content detection.

Simulating the induction welding process of thermoplastic composite materials for aircraft structures

Purpose This paper aims to use two different numerical approaches to simulate the induction welding process for a hybrid thermoplastic material, and the results have been validated experimentally. Design/methodology/approach The first approach used a numerical model that combines electromagnetism, heat transfer and solid mechanics in the same numerical environment using Hexagon Marc software. Simultaneously, a computationally efficient approach combined steady-state electromagnetism results at specific intervals in the Ansys EM suite with heat transfer and solid mechanics in Ansys Workbench. Findings The results from both numerical approaches showed a strong correlation with the experimental findings. Originality/value The current research offers valuable insights into enhancing induction welding procedures within the aerospace industry, as well as across broader industrial applications. The synergistic combination of numerical simulations and experimental validation served as a robust framework for future research endeavors aimed at enhancing the efficiency, reliability and quality of thermoplastic welding techniques.

Impacts of Waste Rubber Products on the Structure and Properties of Modified Asphalt Binder: Part I—Crumb Rubber

The issue of forming a reliable and sustainable structure of crumb-rubber-modified binder is an important scientific and technical task. The quality of this task will increase the technical and economic efficiencies of road construction materials. This work is dedicated to developing a scientifically justified method of directed thermomechanical devulcanization, which ensures the solubility of the crumb rubber in the complex structure of a polydisperse composite material, preventing the formation of aggregates consisting of unsaturated crumb rubber particles, whose elastic aftereffect causes intensive cracking, especially during low-temperature road operations. The novelty in the first part of this article is due to the fact that, for the first time, the quantitative ratio of the polymer component in the crumb rubber was experimentally determined. The ratio of the polymer component to the total content of the other rubber components in the crumb rubber (CR) was determined to be, on average, 93.3 ± 1.8%. The stabilities of the compositions of crumb rubber from different batches were experimentally studied. The nature of the polymer component in the crumb rubber was determined. A hypothesis was formulated to obtain a thermodynamically stable and sustainable binder modified with crumb rubber. To evaluate the compatibility of hydrocarbon plasticizers with the studied CR samples, the following semi-empirical and thermodynamic compatibility parameters were calculated: Hildebrand solubility parameters based on evaporation energy and surface tension, Barstein’s compatibility parameter |X|, Traxler coefficient, and the mass ratio of paraffin naphthene:asphaltenes. It was shown that for the substances under study, it is advisable to justify the choice of plasticizer based on chemical compatibility criteria. It was established that a supramolecular plasticization mechanism occurs in the “hydrocarbon plasticizer–crumb rubber” systems under consideration. In the development of the crumb-rubber-modified binder, it was found that the use of activated crumb rubber (ACR) from large tires does not ensure the achievement of a stable and resilient structure of the crumb-rubber-modified bitumen.

Regulation of the Phase Structure in the Crystallizing Curing System PCL–DGEBA

Qualitative and quantitative aspects of the formation of various types of phase structures, sizes and compositions were considered. For the studied polycaprolactone–epoxy resin/4,4′-diaminediphenylsulfone system, a phase diagram characterized by amorphous separation with a lower critical solution temperature was constructed and its evolution was traced with increasing conversion degree of epoxy groups. A method is proposed for determining the temperature–concentration parameters that determine the type of phase structure of composite materials, based on the optical interferometry method. All types of phase structures and features of structure formation in the phase reversal region and at its boundaries have been studied using optical and scanning electron microscopy methods. The dimensions of the structural elements were determined and their correlation with the temperature and concentration regimes of the system’s curing was established. The composition of phases in cured compositions was studied using FTIR spectroscopy, DSC and scanning electron microscopy. It is shown that by varying the temperature–concentration parameters of curing reactive thermoplastic systems, it is possible to specifically regulate the type of phase structure, phase sizes and their composition, which determine the operational properties of the material.

Advancing structural health monitoring: Deep learning-enhanced quantitative analysis of damage in composite laminates using surface strain field

Composite materials have been widely used as critical components in aerospace applications due to their excellent performance characteristics. The real-time accurate identification and quantification of various types of damage within composite material structures pose a significant challenge. This study introduces an innovative damage detection method based on strain fields, which centrally employs deep learning techniques. Utilizing the Res-Mask R–CNN, this study accurately detects and categorizes various forms of damage within composite laminates, including open holes, subsurface holes, and delamination. Moreover, this method also enables precise localization and quantification of damaged areas. A series of experiments and simulations have validated the accuracy and robustness of the network model. Damage inversion experiments demonstrate that the area error of the damaged regions has been reduced to 7.4 %, and the positional error does not exceed 3.31 mm. In simulated scenarios, the shape context distance for complex damage contours does not exceed 0.21, indicating that the critical geometric features of the damage have been successfully preserved. This study provides an effective new approach for damage detection and real-time structural health monitoring of composite laminates.

Research on composite material riveting simulation method for engineering applications

PurposeIn order to improve the efficiency and reliability of simulation analysis for composite riveting structures in engineering products, a comparative study was conducted on different forms of riveting simulation methods.Design/methodology/approachFive different rivent simulation models were established using the finite element method, including rigid element CE, flexible element Rbe3 and beam element, and their results were future compared and analyzed.FindingsUnder the given technical parameters, the simulation method of Rbe3 (with holes) + beam can meet the analysis requirements of complex engineering products in terms of the rationality of rivet load distribution, calculation error and relatively efficient modeling.Originality/valueThis study proposes a simulation method for the riveting structure of carbon fiber composite materials for engineering applications. This method can satisfy the simulation analysis requirements of transportation vehicles in terms of modeling time, computational efficiency and accuracy. The research can provide technical support for the riveting process and mechanical analysis between carbon fiber composite components in transportation products.

Methodology for optimizing the radio absorption capacity and mechanical strength of composite structural materials

The possibility of impregnating high-strength fabrics under pressure with a modified binder is considered. The development of high-temperature composites that have not only high strength, but also microwave absorption properties is inextricably linked with new products being developed and the imposition of more stringent tactical and technical requirements on them. For the successful introduction of these composites into the field of mechanical engineering, one of the necessary conditions is the assessment of their stress-strain state at the design stage. This method allows producing the fabric for aircraft details with high strength. The purpose of the study is to evaluate the absorption of microwave waves and study the physical and mechanical characteristics of composites obtained by vacuum infusion.