Structure Of Composite Materials Research Articles

Influence of sodium on the structure and properties of aluminum matrix composite materials based on pseudobinary eutectic

Influence of sodium on the structure and properties of aluminum matrix composite materials based on pseudobinary eutectic

Mesoporous polymer supported Metal-Based deep eutectic solvents for enhanced capture of Low-Content Ammonia

The capture the low-content NH3 from industrial streams, and recycle it as the feedstocks for industrial processes is very important. In this work, we reported the use of mesoporous polydivinylbenzene (PDVB) as the support of metal-based deep eutectic solvents (DESs) containing choline chloride (ChCl) and metal chlorides (SnCl2, FeCl3 or ZnCl2) for NH3 capture. The structure of composite materials was characterized in details, and the NH3 capture performance and mechanism of them were also examined in depth. Owing to the coordination interaction of metal ions with NH3, along with the hydrogen-bond interaction of − OH and Cl− with NH3, the DES@PDVB composites exhibit considerably high low-content NH3 capacities. The optimized sample ChCl + 2ZnCl2@PDVB-1.5 can adsorb 7.43 mol/kg of NH3 at 25 ℃ and 0.122 bar, which is advantageous over most other adsorbents fabricated in the literature. The mechanism of NH3 capture by DES@PDVB composites was also illustrated through spectroscopic characterizations.

Analysis of compression deformation of water-lubricated bearing material based on rigid and flexible substances coupled with microstructure

Water-lubricated bearings are pivotal components in ship propulsion shafting, The mechanical properties of composite materials serve as the foundation for water-lubricated bearing materials. In this paper, taking the 3D composite structure material of arthropod outer carapace as a biological model, a bionic design of a water-lubricated bearing composite material based on rigid and flexible substances coupled with microstructure is proposed, and its load-carrying properties are analyzed through simulation and experimentation. The research results showed that the rigid fiber helix angle of 30° would be better for enhancing mechanical performance. When the basic parameters of the RVE (representative volume elements) are determined, the arrangement of it will also affect the mechanical properties of the composite material to a certain extent, and from the test results, the three RVEs combination mode can obtain better bearing capacity.

Numerical investigation of the low-velocity impact response of 3D orthogonal woven composite plates with preloads

Three-dimensional orthogonal woven composites (3DOWCs) offer significant advantages in engineering applications due to their designability for spatial structures and ability to minimize delamination damage. As primary load-bearing structures, 3DOWCs are always in preloading conditions prior to potential low-velocity impact (LVI) events. This paper presents a macro-meso coupled finite element (FE) model for investigating the response of preloaded 3DOWCs subjected to LVI. The accuracy of the proposed numerical model is validated by a comparison with available experimental data in terms of impact performance and damage state. Furthermore, the influence of preload and impactor shape on the LVI performance of 3DOWCs is examined, and detailed analysis is provided regarding the associated damage mechanisms. This study offers a transferable numerical approach that can be applied to studying the coupling problems of LVI and preload in other textile composite structures.

Research on fatigue performance of “sandwich metal-structured ” composite materials in ultra-low temperature environments

The aim is to investigate the influence of aluminum content in the FeCoCrNiAlx series high-entropy alloys, different aluminum alloy damping layers, and the thickness of damping layers on the fatigue performance of sandwich structure composite material plates after room temperature and low-temperature aging treatment. By using abaqus/fe-safe simulation, as well as liquid nitrogen low-temperature aging treatment and fatigue tensile testing, the differences in fatigue performance between composite materials treated with low-temperature aging and those untreated at room temperature were observed. The increase in aluminum content significantly improves the lifespan of the composite materials, and after low-temperature aging treatment, the change in strength is even more pronounced. Keeping the thickness and material of the upper and lower layers constant, the tensile life of the material, both untreated and treated at low temperatures, shows a significant increasing trend as the thickness of the middle damping layer increases. Other conditions being equal, the iMPact of different damping layer aluminum alloys on fatigue performance is also very evident. In terms of tensile cycles, the ranking is as follows: 7075 > 2A12 > 6061. After low-temperature treatment, the fatigue tension cycles of the 2A12, 6061, and 7075 damping layers under a force of 100 N are respectively 8.66, 7.43, and 2.01 times those of the untreated composite materials.

The Microstructure and Mechanical Properties of Si3N4f/BN/SiBCN Microcomposites Fabricated by the PIP Process.

SiBCN ceramics based on SiC, BN and Si3N4 structures have good comprehensive properties such as high-temperature resistance, oxidation resistance, creep resistance and long life, which makes it one of the very promising ceramic material systems in military and aerospace fields, etc. In this study, SiBCN ceramics, as well as Si3N4f/BN/SiBCN microcomposites, were prepared by a polymer infiltration pyrolysis method using PBSZ as the polymer precursor. The PBSZ was completely ceramized by pyrolysis at 900 °C. The weight loss and elemental bonding forms of the products after the pyrolysis of the precursors hardly changed from 600 °C to 900 °C. After pyrolysis at 600 °C for 4 h and using the BN coating obtained from twice deposition as the interfacial phase, a more desirable weak interface of fiber/matrix with a binding strength of 21.96 ± 2.01 MPa can be obtained. Si3N4f/BN/SiBCN ceramic matrix microcomposites prepared under the same pyrolysis conditions have a relatively good tensile strength of 111.10 MPa while retaining a weak interface between the fibers and the matrix. The results of the study provide more theoretical and methodological support for the application of new composite structural ceramic material systems.

Fast computational approach with prior dimension reduction for three-dimensional chemical component analysis using CT data of spectral imaging.

Spectral image (SI) measurement techniques, such as X-ray absorption fine structure (XAFS) imaging and scanning transmission electron microscopy (STEM) with energy-dispersive X-ray spectroscopy (EDS) or electron energy loss spectroscopy (EELS), are useful for identifying chemical structures in composite materials. Machine-learning techniques have been developed for automatic analysis of SI data, and their usefulness has been proven. Recently, an extended measurement technique combining SI with a computed tomography (CT) technique (CT-SI), such as CT-XAFS and STEM-EDS/EELS tomography, was developed to identify the three-dimensional (3D) structures of chemical components. CT-SI analysis can be conducted by combining CT reconstruction algorithms and chemical component analysis based on machine learning techniques. However, this analysis incurs high computational costs owing to the size of the CT-SI datasets. To address this problem, this study proposed a fast computational approach for 3D chemical component analysis in an unsupervised learning setting. The primary idea for reducing the computational cost involved compressing the CT-SI data prior to CT computation and performing 3D reconstruction and chemical component analysis on the compressed data. The proposed approach significantly reduced the computational cost without losing information about the 3D structure and chemical components. We experimentally evaluated the proposed approach using synthetic and real CT-XAFS data, which demonstrated that our approach achieved a significantly faster computational speed than the conventional approach while maintaining analysis performance. As the proposed procedure can be implemented with any CT algorithm, it is expected to accelerate 3D analyses with sparse regularized CT algorithms in noisy and sparse CT-SI datasets.

High fidelity FEM based on deep learning for arbitrary composite material structure

Due to the outstanding performance, composite materials are widely used and analyzing their properties and designing them based on performance has become a crucial task in the field of many manufacturing industries. Composite materials possess complex multiscale structures, and traditional fine-scale finite element modeling and analysis may lead to severe computational resource challenges. To overcome this difficulty, breakthroughs in key technologies of multiscale accelerated analysis algorithms are required. In this study, an innovative approach based on artificial intelligence and multiscale finite element method is presented. This approach involves partitioning the entire composite material structure into coarse grids that resemble homogenous structures of similar size, providing results consistent to fine-grid finite element analysis. By utilizing CNN for image feature recognition and employing the CGAN adversarial method, coarse-grid equivalent stiffness matrices and multiscale shape functions from completely random microstructures of composite materials can be obtained. Consequently, this enables a rapid response process from microstructure to low-resolution grid to high-resolution physical field, with remarkably accurate physical field results. Moreover, compared to traditional fine-grid finite element methods, this approach significantly reduces memory usage and computation time. This method is applicable to composite materials with varying shaped inclusions, different component properties, and diverse geometric distributions, allowing these materials to perform high-fidelity finite element calculations on coarse grids and predict their mechanical behavior. Furthermore, this breakthrough opens avenues for accelerating the optimization design of composite materials with diverse mechanical functionalities, by employing a bottom-up approach.

Adhesive Strength in the Structure of Composite Materials Based on Organic Raw Materials

This article discusses issues related to correcting the adhesive properties of composite materials based on organic waste and expanded polystyrene. The theoretical prerequisites for the formation of the structure of materials based on organic raw materials are determined. An average series of binders has been established as the adhesive strength with vegetable filler increases. The results of determining the adhesive strength of polystyrene foam in the structure of the composite material are presented. In order to increase the hydrophilicity of polystyrene foam, such binders as polyvinyl acetate emulsion, liquid glass, and acrylic latex were used in research. Analysis of the results obtained allows us to evaluate the effectiveness of the binder and determine the optimal type of filler in the composition of the composite material, based on the values of the shear strength. As a result, it was found that the introduction of expanded polystyrene into the composition of a composite material based on organic raw materials makes it possible to reduce the consumption of the binder by 82–87% due to its treatment with an aqueous solution of dimethyl ketone and providing it with adhesive ability. Thus, it is possible to significantly increase the share of organic waste used in the production of building materials, increasing the efficiency of their processing and disposal.

Study on mechanical properties of bolted connection structure of carbon fiber resin matrix composites at low temperature

This article focuses on the impact of low temperature environments that composite materials may face in engineering applications. Through experimental testing, the bearing capacity of carbon fiber resin based composite bolted structures at -100 ℃ and 25 ℃ was obtained, and a continuous damage model (CDM) was established. The damage evolution mechanism of bolted connection structures between metal and carbon fiber resin matrix composites at -100 °C and 25 °C was elucidated through numerical simulation. Research has shown that the ultimate load of the structure at -100 °C is 3.99% lower than that at room temperature, and the failure mode of the composite material structure at low temperature is transverse fracture along the hole edge, which is different from the compression tensile fracture along the nail hole section at room temperature.

Nanoarchitectonics of high-performance TiO2/C composites from Ti4+-coordination crosslinked Pickering emulsion gel

TiO2/C composites have been developed from polysaccharide-Ti4+ complex to photodegrade methylene blue (MB) but with low BET surface area. The present study aimed to obtain TiO2/C composite materials with improved BET surface area by Ti4+-coordination crosslinked Pickering emulsion gel. FT-IR, UV–vis, XRD, XPS, UV–vis DRS, TG-DTA, PEC, N2 adsorption-desorption, SEM-EDS, and TEM were used to characterize the morphology and structure of the as-prepared composite materials. The composites showed enhanced BET surface area with uniform particle size, in which the TiO2 was distributed uniformly. Carbon is mainly present on the surface, which facilitates the separation of charge carriers. The photodegradation properties of the obtained composite materials were investigated. TiO2/C composite prepared at 500 °C has excellent adsorption and photodegradation performance, and 98.91 % of MB was removed within 40 min. In addition, the composite material has good cycling stability. Overall, a simple and efficient method for TiO2/C preparation was proposed, which can be promoted to other polysaccharides.

Detection and Analysis of Aircraft Composite Material Structures Using UAV

Pre-flight inspection and maintenance are essential prerequisites for aviation safety. This study focused on developing a real-time monitoring system designed to assess the condition of composite material structures on the exterior of aircraft. Implementing such a system can reduce operational costs, enhance flight safety, and increase aircraft availability. This study aims to detect defects in aircraft fuselages manufactured from composite materials by applying image visual recognition technology. This study integrated a drone and an infrared camera for real-time image transmission to ground stations. MATLAB image analysis software (MATLAB 2020b) was used to analyze infrared (IR) images and detect structural defects in the aircraft’s appearance. This methodology was based on the inspection of damaged engine cowlings. The developed approach compares composite material conditions with known defects before and after repair, considering mechanical performance, defect size, and strength. Simultaneously, tests were conducted on various composite material panels with unknown defects, yielding favorable results. This study underscores an integrated system offering rapid detection, real-time feedback, and analysis, effectively reducing time, and potential hazards associated with high-altitude operations. Furthermore, it addresses blind spots in aircraft inspections, contributing to effective flight safety maintenance.

The Potential of Multi-Task Learning in CFDST Design: Load-Bearing Capacity Design with Three MTL Models.

Concrete-filled double steel tubes (CFDSTs) are a load-bearing structure of composite materials. By combining concrete and steel pipes in a nested structure, the performance of the column will be greatly improved. The performance of CFDSTs is closely related to their design. However, existing codes for CFDST design often focus on how to verify the reliability of a design, but specific design parameters cannot be directly provided. As a machine learning technique that can simultaneously learn multiple related tasks, multi-task learning (MTL) has great potential in the structural design of CFDSTs. Based on 227 uniaxial compression cases of CFDSTs collected from the literature, this paper utilized three multi-task models (multi-task Lasso, VSTG, and MLS-SVR) separately to provide multiple parameters for CFDST design. To evaluate the accuracy of models, four statistical indicators were adopted (R2, RMSE, RRMSE, and ρ). The experimental results indicated that there was a non-linear relationship among the parameters of CFDSTs. Nevertheless, MLS-SVR was still able to provide an accurate set of design parameters. The coefficient matrices of two linear models, multi-task Lasso and VSTG, revealed the potential connection among CFDST parameters. The latent-task matrix V in VSTG divided the prediction tasks of inner tube diameter, thickness, strength, and concrete strength into three groups. In addition, the limitations of this study and future work are also summarized. This paper provides new ideas for the design of CFDSTs and the study of related codes.

Hierarchical flower bud-like P, W co-doped NiCo2S4@MoS2 composites as high-performance electrodes for asymmetric supercapacitor

Engineering binary transitional metal sulfides (BTMSs)-based electrode materials with a rationally designed constituent architecture is a viable strategy for improving their rate capability and electrochemical durability, which provides a possibility for their application in supercapacitors (SCs). Herein, a novel three-dimensional (3D) flower bud-like phosphorus and tungsten co-doped NiCo2S4 and MoS2 composites (P, W-NCS@MS) is prepared on conductive carbon cloth using the hydrothermal method. The effects of P, W-doping, or MoS2-combination on the morphology, structure and electrochemical properties of NiCo2S4-based electrode materials are systematically studied. The designed P, W-NCS@MS achieves a high specific capacity of 1250C g−1 at 1 A g−1 and a satisfactory capacity retention of 80 % after 10,000 cycles. In addition, the asymmetric supercapacitor (ASC) constructed through P, W-NCS@MS and activated carbon electrodes delivers a high energy density of 65.0 Wh kg−1 at the power density of 400 W kg−1 and shows satisfactory cycling stability of 85 % capacitance retention after 20,000 cycles. Notably, the assembled ASC device successfully powered electronic devices in a serial circuit, highlighting its prospective applications in energy storage. This work offers a viable design approach for heteroatom doping and hierarchical interface structures in composite electrode materials toward high-performance SCs.

Low-velocity impact damage of bionic turtle shell sandwich laminates with different suture shapes

Turtle shells have evolved over millions of years, developing exceptional mechanical properties such as high relative strength and toughness, rendering them highly effective in resisting impacts. This study delves into the impact resistance of bionic turtle shell structures with various suture shapes. This article analyzes the low-velocity impact of carbon fiber epoxy resin prepreg (CF/EP) composite sandwich panels with a suture interface by using the finite element simulation. The simulations encompass closed and unclosed models featuring bonded and unbonded tips, each with diverse trapezoidal geometries (triangular, trapezoidal, anti-trapezoidal, and rectangular). The findings reveal that sandwich structures with suture interfaces demonstrate significantly enhanced impact resistance compared to those lacking sutures, displaying 3–9 times greater deformation capacity and 20–30 times higher energy absorption capacity. The impact resistance of the triangular suture interface exceeded that of other bioinspired suture shapes, with trapezoidal and anti-trapezoidal sutures also enhancing stiffness, strength, and toughness. Additionally, a 6° bonded tip angle resulted in optimal performance for the triangular suture interface across all analyzed perspectives. The simulation study in this paper provides comprehensive and reliable data on low-velocity impact results, offering fundamental insights for researchers to design composite material structures that meet specific mechanical requirements effectively. Additionally, it offers novel ideas for the connection of protective structures, such as artificial armor.

Non-Destructive Testing (NDT) Method for Defect Detection in Glass Fibre Reinforced Plastic/Polymer (GFRP/GRP) Composite Materials Structures: A Review

Various industries are considering metal product in lieu composite materials. Structural engineers appreciate glass fibre reinforced plastic/polymer (GFRP/GRP) because to its high modulus of elasticity, ratio of strength to weight, and corrosion resistance features. It has been discovered that structural engineering defects to be leading cause for the catastrophic consequences. This paper provides an overview of available NDT methods that can be employed to assess the quality of GFRP/GRP composite materials. The most common NDT method used by researchers and practitioners is also discussed, along with the advantages, disadvantages, characteristics, and potential applications of these materials. The review will lead the research using ultrasonic testing as a potential method employing low-frequency transducers with multielement architecture. This study will lead industry players, GFRP/GRP manufacturers, researchers, and NDT practitioners towards the development of technical standards for ultrasonic testing on GFRP/GRP in Malaysia.

Studying the structure of the polyamide-based polymer composite materials obtained by the in situ polymerization of ?-caprolactam and extrusion

Studying the structure of the polyamide-based polymer composite materials obtained by the in situ polymerization of ?-caprolactam and extrusion

Multi-scale design of composite material structures for maximizing fundamental natural frequency

This study deals with the topology optimization (TO) of linear elastic composite structures considering fundamental natural frequency maximization. The concept of functionally graded structures (FGS) is used for anisotropic composite material structure design to improve the structural dynamic performance. The rational approximation of material properties (RAMP) method was employed as an alternative to the solid isotropic material with penalization (SIMP) method to improve the convergence stability for eigen-frequency problem. In the SIMP method, the occurrence of local eigen-modes at low frequencies in the void region causes ill-convergence, whereas the RAMP method prevents local eigen-modes from occurring. The method of moving asymptotes is used as an optimizer. Numerical verification was performed for three structural types: cantilever beam, double-clamped beam, and four-pinned beam structure. In addition, for cantilever beam design, bi-objective optimization for maximizing fundamental natural frequency as well as minimizing structural compliance was performed using the adaptive weighting method that quantitatively reflects the designer's preference by adjusting the weight for each objective function at each iteration.

Load-bearing capacity of composite honeycomb sandwich high-speed train floor

ABSTRACT The honeycomb sandwich structure of composite materials has broad prospects for application in the lightweight design of vehicle bodies. This study investigated the influence of relative density and height on an aluminium honeycomb’s out-of-plane quasi-static compression performance through experiments and simulations. The accuracy of the carbon fibre/aluminium honeycomb sandwich panel’s three-point bending model is verified based on the Hashin failure criterion and experimental validation. Furthermore, the load-bearing capacity of the carbon fibre/aluminium honeycomb sandwich floor is analysed, and the factors influencing the load-bearing capacity of the floor are further explored. The results show that the relative density significantly impacts the out-of-plane quasi-static compression performance of aluminium honeycomb, while the height has a minor influence. Compared with the original CRH5-type floor structure, the carbon fibre/aluminium honeycomb sandwich floor has a weight reduction of 45.23%, and it meets the strength requirements under uniformly distributed and concentrated load conditions. Changing the honeycomb wall thickness and panel thickness distribution can improve the load-bearing capacity of the floor.

Vibration Response of Thermoplastic Veil Interleaved Carbon Fiber Reinforced Epoxy Composites

Plate composite structures are used in many sectors today. Therefore, the demand for these structures is increasing. Especially in the field of aerospace, layered composite structures attract more attention. These wide range of applications affect composite materials in various aspects such as dynamic and mechanical in terms of working environments. Time-dependent variable stresses, vibrations and fatigue that occur in structures subjected to dynamic loads adversely affect both the internal and external structure of composite materials. This situation reduces the safe service life of composite materials. It is an important problem to eliminate or minimize the parameters that negatively affect the economic service life of fiber reinforced layered composite structures. In order to overcome these problems, it is aimed to create new composite structures by adding two different thermoplastic veil layers between fiber fabrics, which are widely used on an industrial basis. In this study, carbon fiber was used as the fiber fabric and Polyamide (PA) and Polyether ether ketone (PEEK) veils were used as the thermoplastic veil layers. The productions were made by Vacuum Assisted Resin Transfer Molding (VARTM) method and dynamic (natural frequency and damping ratio) tests were performed according to the relevant ASTM standards. With the experimental results obtained, the dynamic properties of thermoplastic veil-layered carbon fiber/epoxy composites were comparatively investigated to determine the effect of both veil layers and different fiber contents.