Composite Materials Research Articles

MODELING OF HIGH-RATE HARDENING OF A POLYMER COMPOSITE MATERIAL UNDER LOADING ALONG THE REINFORCEMENT DIRECTION

Modeling the high-rate deformation of composite structures is of great interest in the industry. Moreover, some processes such as accidents, explosions and possible impact issues require analysis of composite materials at significantly high deformation rates. The paper considers the possibility of developing a model of deformation of a composite material based on a polymer matrix and carbon fiber taking into account high-rate hardening. A feature of the study is the development of a model that takes into account a wide range of deformation rates from static to several thousand reverse seconds. Thus, tests were carried out with special equipment and samples that allow us to obtain data with such high loading speeds. The model is based on an approach considering the use of damage parameters, the so-called class of models with progressive degradation. The main innovative part of the chosen model is the formalization of the rate of deformation on the material through the damage parameter, that is, the rate of change in damage values is considered. This approach makes it possible to make constitutive relations based only on the damage parameters, which modify the stiffness and strength characteristics of composites, which greatly simplifies the modeling and analysis of material deformation.

MOF-Based Guided Bone Regeneration Membrane for Promoting Osteogenesis by Regulating Bone Microenvironment through Cascade Effects.

Regulation of bone microenvironment (BME) including innate pH values and metal ions affects cellular functions and activities of osteoblasts and osteoclasts, thereby significantly influencing the process of bone regeneration. How to achieve multiple effective regulations of the BME through cascade effects via facile material design and fabrication to significantly facilitate osteogenesis remains a challenge. Herein, a facilely-designed resorbable guided bone regeneration membrane (PCL/DEX@Ca-Zol) based on a drug-loaded metal-organic framework is reported. Thereinto, calcium ions, zoledronic acid, and dexamethasone embedded in the membrane can be responsively released specifically inside bone defect in an acid-triggered manner to synergistically regulate BME by neutralization of pH value, enhancement of osteogenic differentiation and mineralization, and inhibition of osteoclasts in one-go. Along with polycaprolactone as a structural support in the membrane for bone regeneration with fully utilized components of the composite membrane material, enhances bone regeneration with minimized side effects is accordingly achieved with the assistance of effective modulation of BME through multiple cascade effects.

Integrated Carbon Nanotube and Ketoenamine-Linked Covalent Organic Framework with Positive Charge Structure as High-Performance Capacitive Materials.

A series of composite materials, ETB@CNT (ETB@CNT10, ETB@CNT20, ETB@CNT30, ETB@CNT40, ETB@CNT50) with different carbon nanotubes (CNTs) contents are successfully prepared by using one-pot method. Compared with the pure ET-B-COF, which is a ketoenamine-linked covalent organic framework (COF) with a positive charge structure, CNTs can effectively improve the electrochemical performance of ET-B-COF, and the specific capacitance increased with the increase of the mass of carbon nanotubes added during the preparation process. Among them, ETB@CNT40 exhibits the best electrochemical performance (37.6 F g-1) at a current density of 1 A g-1. This study indicates that the simultaneous introduction of CNTs into COFs can significantly improve the electrochemical performance of ketoenamine-linked COFs materials.

Lipid Membrane Domains Control Actin Network Viscoelasticity.

The mammalian cell membrane is embedded with biomolecular condensates of protein and lipid clusters, which interact with an underlying viscoelastic cytoskeleton network to organize the cell surface and mechanically interact with the extracellular environment. However, the mechanical and thermodynamic interplay between the viscoelastic network and liquid-liquid phase separation of 2-dimensional (2D) lipid condensates remains poorly understood. Here, we engineer materials composed of 2D lipid membrane condensates embedded within a thin viscoelastic actin network. The network generates localized anisotropic stresses that deform lipid condensates into triangular morphologies with sharp edges and corners, shapes unseen in many 3D composite gels. Kinetic coarsening of phase-separating lipid condensates accelerates the viscoelastic relaxation of the network, leading to an effectively softer composite material over intermediate time scales. We dynamically manipulate the membrane composition to control the elastic-to-viscous crossover of the network. Such viscoelastic composite membranes may enable the development of coatings, catalytic surfaces, separation membranes, and other interfaces with tunable spatial organization and plasticity mechanisms.

Comparing numerical simulation methods for evaluating hysteretic response of self-centering shear walls reinforced with SMA-ECC under cyclic loading

Under the action of earthquake, the traditional shear wall structure has the problems of excessive residual deformation and macroscopic cracks. The SMA-ECC composite material formed by the combination of smart materials such as shape memory alloy (SMA) and high ductility engineered cementitious composite (ECC) not only has good energy dissipation capacity, but also can obtain superior self-centering ability and damage self-healing ability, thereby improving the seismic performance and durability of shear wall structures. In this paper, in order to explore the nonlinear behavior of the self-centering shear wall under earthquake action and accurately simulate it, ECC and SMA material tests are carried out to establish the uniaxial constitutive relationship of the material. Using OpenSees finite element analysis platform, considering the micro and macro perspectives, a variety of finite element models are established, namely layered shell model, fiber model and multi-vertical rod model. Combined with the low-cycle reciprocating loading test of shear walls, the numerical simulation results are compared with the experimental data. By considering the parameters such as yield load, peak load and simulation time, the feasibility, stability and calculation efficiency of these models are evaluated. The results show that among the three models, the model based on fiber element can capture well the hysteretic response of new materials, and simulate the hysteretic performance, pinch effect and stiffness degradation of various shear wall members. The simulated values and experimental values can be well matched. Compared with the microscopic model, the computational efficiency of the fiber model is greatly improved, and the model has good feasibility, accuracy and efficiency.This work provides a basis for further research on the optimization of design parameters of SMA-ECC shear wall.

Preparation of Composite Materials with Slow-Release Biocides and Solidifying Agents for Remediation of Acid Pollution in Coal Gangue

The processes of coal mining and washing generate a substantial amount of coal gangue. During prolonged outdoor storage, this waste can lead to both direct and indirect environmental pollution, as well as geological hazards. Recent research has indicated that the redox processes of coal gangue are regulated by microorganisms. Techniques such as the application of biocides and the facilitation of microbial interactions have proven effective in controlling the acidic pollution of coal gangue in the short term. However, conventional doping methods that couple sulfate-reducing bacteria with biocides face challenges, including a short effective duration and poor stability. To address these issues, this study utilized corn straw biochar as a microbial attachment material and incorporated water-retaining agents as slow-release biocide carriers, resulting in the development of an environmentally friendly microbial remediation material. This study selected 0.6 g of biochar produced from the pyrolysis of corn straw at 700 °C to immobilize sulfate-reducing bacteria. Additionally, 0.6 g of polyacrylamide was used to prepare a slow-release bactericide with 100 mL of a sodium dodecyl sulfate solution at a concentration of 50 mg·L−1. The composite remediation material successfully raises the pH of weathered coal gangue leachate from 4.32 to 6.88. Its addition notably reduces the sulfate ion concentration in the weathered coal gangue, with sulfate content decreasing by 86.45%. Additionally, the composite material effectively lowers the salinity of the weathered coal gangue. The composite immobilizes heavy metal ions within the weathered coal gangue, achieving an approximate removal rate of 80% over 30 days. Following the introduction of the composite material, significant changes were observed in the dominant microbial communities and population abundances on the surface of the coal gangue. The composite demonstrated the ability to rapidly, sustainably, and effectively remediate the acidification pollution associated with coal gangue.

Fabrication of a Composite Paper-Based Material for Fog Collection and Purification Enabled by Passive Radiative Cooling and Wettability Regulation.

Obtaining clean freshwater resources with high efficiency is a global concern and plays a vital role in the sustainable development of human society. In this study, purified freshwater was obtained via condensation and collection of water and organic fog using a composite paper-based material with spectral selectivity and proper wettability. By reflecting ∼91% of sunlight and radiating >96% of thermal infrared rays, the composite paper-based material can reach a daytime maximum temperature drop of 5.2 °C compared to pristine paper and 6.7 °C compared to environmental temperature. Furthermore, surface wettability can be easily adjusted by optimizing the wettability of the nanoparticles. Under the combined effect of excellent passive daytime radiative cooling performance and an appropriate wettability range, a maximum water collection rate of 332.09 mg/cm2·h under dynamic vapor atmosphere and 245.10 mg/cm2·h under static vapor atmosphere were obtained. Even for mixed organic fogs, purified water can be collected after organic fog condensation because of its high selectivity for different liquids. In addition, the composite paper-based material exhibited excellent abrasion resistance and has great potential for long-term use and reuse. This composite paper-based material can obtain freshwater via water and organic fog condensation and collection under direct sunlight, which is helpful in alleviating freshwater shortages.

Ecosystem [512]: Acoustic Ecology Surveys as Music

Acoustic ecology is a rapidly expanding discipline which can reveal details about ecosystems that are not visually apparent, and field recording has been used in an increasing variety of ways in music compositions, opening the door to collaborative projects that walk the line between science and art. Ecosystem [512] is rooted in acoustic surveys that I carried out over nine months in Iceland’s National Parks. These surveys provided more than 10,000 hours of recordings that are processed, compressed, combined, and analyzed before being used as the fundamental material for a music composition for electronics and clarinet. The piece uses multiple strategies such as algorithmic composition to handle the transition from rough acoustic survey recordings to final music product. The process of composing this piece reveal insights about both acoustic ecology processes and music composition considerations.

Construction of N-doped carbon/MnO nanoparticles/hollow carbon spheres nested structure with tunable valence state for high-performance aqueous zinc ion batteries enables 10000 cycling stability

The practical applications of manganese-based aqueous zinc ion batteries (AZIBs) have been hindered by issues such as structural collapse, dissolution of active substances, and poor conductivity. Herein, a novel N-doped carbon/MnO nanoparticles/hollow carbon spheres nested structure (HCSs@MnO@NC) is fabricated as the active cathode material for AZIBs by controlled carbothermal reduction strategy. The internal hollow structure mitigates the volume expansion of MnO and improves material stability. The Mn-O-C heterojunction structure accelerates charge transfer and enhances structural stability. By controlling the carbothermal reduction process to adjust the valence state, electrochemical determinations demonstrate that divalent manganese exhibits a higher capacitance contribution rate, which is conducive to a faster ion migration rate. In situ UV–vis is firstly employed to detect the change of Mn2+ concentration in the electrolyte, revealing a Mn2+ deposition phenomenon in addition to the ion embedding mechanism during the initial charge. Owing to these favorable structural characteristics, the prepared HCSs@MnO@NC cathode delivers a specific capacity of 320.5 mAh g−1 at 0.1 A g−1 and maintains an excellent capacity after 10,000 cycles at 3 A g−1. This work can provide a new pathway for constructing advanced AZIBs by optimizing the nanostructure of composite electrode materials.

Design of a “binaural” hydroacoustic transducer

Purpose This study aims to design a piezoelectric sensor with high performance transmitting and receiving functions, which is characterized by simple structure and multifunctionality. Design/methodology/approach In accordance with the binaural principle, a binaural-sensitive element is constructed with the middle module transmitting the signal and the left and right modules receiving the signal. The traditional 1-3-2 piezoelectric composite material is selected for the sensitive element of the transmitting module, while the improved 1-3-2 piezoelectric composite material is selected for the sensitive element of the receiving module. The impact of varying the thickness of the transmitting module on its resonance frequency and the influence of varying the thickness of the receiving module on its anti-resonance frequency were investigated through simulations conducted using ANSYS finite element software. This was done to ascertain the optimal thickness dimensions and operating frequencies for the binaural sensitive elements. Findings At last, binaural transducers were constructed and subjected to experimental evaluation within an anechoic chamber. The experimental results demonstrate that the operating frequency of both the transmitting and receiving modules is 150 kHz, the transmitting voltage response is 160 dB, and the receiving sensitivity of the “left ear” is −192 dB, and the receiving sensitivity of the “right ear” is −190 dB. The objective of achieving high-performance transmitting and receiving within the same frequency range has been met. Originality/value A binaural sensitive element is proposed to realize high-performance transmission and reception in the same frequency range.

Statistical Methods in the Analysis of the Effect of Carbonisate on the Hardness of Epoxy-Resin-Based Composites

This research concerns the manufacture and characterisation of epoxy composites with the addition of carbonisate, obtained by the pyrolysis of MDF (medium-density fibreboard) furniture board waste. The laminated composites were made by hand lamination, with the carbonisate used as a filler to improve the mechanical properties of the composite. The carbonisate was obtained by the thermal decomposition of MDF waste in an anaerobic environment by pyrolysis, which is an efficient method of waste management and material recycling. The resulting carbonisate was integrated into an epoxy resin matrix to investigate its potential as a reinforcing agent. The article describes a study on the hardness of epoxy-resin-based composites to which carbonisate was added in different fractions and percentages. The aim of the research was to test the possibility of using char as a component in improving the mechanical properties of epoxy composites with a view towards creating a durable recycled material with optimal parameters. As part of the study, a statistical analysis of the results of hardness measurements was carried out to accurately assess the effect of the quantity and size of the carbonate particles on the mechanical properties of the materials. The analysis identified significant differences between samples and verified the repeatability of the results. It was found that the addition of carbonisate to the A0 base sample (without the addition of carbonisate) leads to a significant hardening of the material. This was confirmed by the higher medians of samples A01 (carbonisate 5% with a 0.5 mm fraction), A02 (carbonisate 7.5% with a 0.5 mm fraction), and A03 (carbonisate 5% with a 1.0 mm fraction) compared to the base sample. The most homogeneous hardness was shown in sample A02, with the highest concentration of results and the lowest values of standard deviation and spread. The results indicated that the addition of carbonate significantly increased the hardness of the composite materials, with optimal stability achieved at 7.5% (by weight) of carbonate with a 0.5 mm fraction. The conducted research precisely determined the influence of the amount and characteristics of carbonisate particles on the mechanical properties of the materials, which enables the more effective designing of future composites. The statistical results provide a reliable basis for evaluating the potential applications of these materials in various industrial sectors, such as construction, automotive and aerospace, where high hardness and durability are important.

Design and characterization of natural fiber reinforced cotton-epoxy composites

This research paper focuses on the design and fabrication of natural cotton epoxy composites. By combining natural cotton fibers with epoxy resin, the study aims to develop composite materials with desirable mechanical properties. To evaluate their performance, the composites were subjected to three-point bending tests, which revealed an average flexural strength of 50 MPa and a flexural modulus of 3.8 GPa, highlighting the material’s capacity to bear bending loads. The bending tests provided insights into the composite’s response to flexural loads, including its strength, stiffness, and failure mechanisms. Post-test analysis using an optical microscope revealed that the primary failure modes included delamination and fiber breakage. Delamination, characterized by the separation of layers within the composite, and fiber breakage, caused by the fibers’ inability to withstand stress exceeding their tensile strength of approximately 300 MPa, led to crack propagation through the material. These findings indicate that the composite's failure was primarily driven by these mechanisms. This study provides valuable insights into improving the composite's design and enhancing its mechanical properties, contributing to the broader understanding of natural fiber-reinforced composites and their behavior under mechanical stress.

Design of a UV Chamber for Studying the Destruction of Polymer Composite Materials (Review)

Design of a UV Chamber for Studying the Destruction of Polymer Composite Materials (Review)

Technology for Processing Composite Materials Based on Polylactide Using 3D Printing: Properties and Structure

Technology for Processing Composite Materials Based on Polylactide Using 3D Printing: Properties and Structure

Analysis of the Thermomechanical Behavior of SiC/Si/TiSi<sub>2</sub> Cermets Manufactured with Waste Wood from Capirona and Capinuri Peruvian Species

This study analyzes the thermomechanical behavior of SiC/Si/TiSi2 cermets manufactured from Peruvian wood waste of the Capirona and Capinuri species. A sustainable manufacturing process was used that uses sawdust as a precursor. The mechanical properties under compression and the elastic modulus of the cermets were characterized from room temperature to 1400°C. At room temperature, the values achieved exceed 500 MPa in both cermets, with the Capinuri precursor being slightly higher in maximum compressive strength with 691 MPa, but in elastic modulus, the Capirona cermet has a rigidity of 159 GPa. At 500°C, the cermets showed a small reduction in their mechanical performance. At 1100°C, a decrease in strength was observed to 248 MPa for Capinuri and 292 MPa for Capirona and in Young's modulus to 85.18 GPa and 91.92 GPa respectively. At 1400°C, both cermets suffered a significant deterioration of their mechanical properties due to a presumed chemical degradation of the individual components. The results demonstrate the feasibility of using wood waste as precursors for the sustainable manufacturing of advanced composite materials, however, optimization of manufacturing parameters and processes should be considered to improve the performance and stability of this material.

Mechanically anisotropic phantoms for magnetic resonance elastography.

Imaging phantoms with known anisotropic mechanical properties are needed to evaluate magnetic resonance elastography (MRE) methods to estimate anisotropic parameters. The aims of this study were to fabricate mechanically anisotropic MRE phantoms, characterize their mechanical behavior by direct testing, then assess the accuracy of MRE estimates of anisotropic properties using a transversely isotropic nonlinear inversion (TI-NLI) algorithm. Directionally scaled and unscaled lattices were designed to exhibit anisotropic or isotropic mechanical properties. Lattices were three-dimensionally printed in poly(ethelyne glycol) diacrylate using a commercial digital light processing printer, then infilled with gelatin to form a composite material. Benchtop testing determined two shear stiffnesses, and , governing loading parallel and perpendicular to the symmetry axis, and two analogous Young's moduli and . From these measures, shear anisotropy = and tensile anisotropy = were calculated. Three phantoms were driven by a central actuator and imaged with MRE at frequencies from 300 to 500 Hz. From MRE data, the TI-NLI algorithm estimated maps of , , and . In benchtop tests, geometrically scaled lattice composites exhibited the following anisotropic properties: = 6.1 ± 0.7 kPa, = 0.83 ± 0.13, = 0.78 ± 0.09} (mean ± standard deviation). MRE of scaled lattice composites revealed elliptical wavefields; TI-NLI analysis identified the following median property ranges: = 11-19 kPa, = 0.6-1.0, = 0.8-1.6}. Anisotropic MRE phantoms are created by embedding anisotropic three-dimensionally printed lattices into a softer matrix. The TI-NLI algorithm accurately estimates spatial contrast in anisotropic properties.

Design of a two-seater seaplane wing spar structure with composite materials

A two-seater, mono-wing seaplane was initially developed for survey and rescue operations, with an empty weight of 470 kg and a maximum takeoff weight of 650 kg. Fiber-reinforced composite materials, consisting of fiber reinforcement and thermosetting polymer, were used in this airframe to reduce weight because the structural properties can be customized by adjusting the orientation of the fiber fabric layup and removing redundant material, which is impossible with metal. This paper presents a comprehensive overview of the design process for the aircraft's primary I-beam wing spar, employing composite material. Before conducting design calculations, it is critical to consider the variability of characteristics of composite materials caused by fabrication conditions such as temperature, humidity, and defects. As a result, it is imperative to conduct thorough testing of carbon fiber-reinforced composites following many different testing requirements. The coupon tests capture critical characteristics such as strength, stiffness, and Poisson's ratio across several orientations. The wing spar I-beam structure was subsequently developed with three primary considerations: stiffness (maximum deflection), strength, and stability (structural buckling). Following preliminary sizing of the I-beam wing spar, a simple initial layup was recommended, with primary loading in each component. The initial design was then subjected to a more detailed calculation using classical lamination theory, which took into account distributed load along the wing, spar taper, ply-drops along the span, and composite layup guidelines in order to reduce structural weight while ensuring the main spar's ability to withstand operational loads effectively. The calculating results show that the spar with an optimized composite design has a lighter weight than the original design by around 43%, while it can withstand the same loads with no analytical failure.

Numerical study on the flexural and shear behavior of steel fiber and high‐strength steel combination in ultra‐high‐performance fiber‐reinforced concrete beams under cyclic loading

AbstractFiber‐reinforced concrete consists of hydraulic cement, water, aggregate, and discrete fibers, making it a composite material. These fibers, available in different shapes, sizes, and materials such as steel, polymer, glass, and natural fibers, are commonly utilized in structural applications. The tensile strength of conventional concrete tends to decrease as micro‐cracks develop rapidly under applied stresses. However, incorporating closely spaced fibers can hinder the progression of micro‐cracks, leading to a substantial improvement in both tensile and flexural strengths of concrete. Furthermore, fibers can delay the initiation of tensile cracks, effectively enhancing concrete's ability to withstand tensile strains before failure. As a result, fiber‐reinforced concrete exhibits increased durability and enhanced resistance to impacts compared to plain concrete. This study aims to evaluate and compare the cyclic flexural behavior of a cantilever beam constructed from ultra‐high‐performance fiber‐reinforced concrete (UHPFRC) using reinforcing bars made of high‐strength steel (HSS). The beams contain varying relative proportions of longitudinal reinforcement and steel fibers. Various key performance parameters of the cantilever beam were thoroughly examined, such as load capacity, flexural ductility, failure mode, hysteresis response, energy dissipation, and hardness. The study demonstrated that UHPFRC beams with HSS exhibit good cyclic flexural performance prior to failure.

Effect on Mechanical Property of Polypropylene Mixed with Charcoal Waste Ash through Melt Compounding

This study explores the use of charcoal waste ash, a by-product of human activities, as a filler in polypropylene matrices. The samples were mixed using the melt compounding method using an internal mixer at 1wt%, 2wt%, 5wt%, 7wt% and 10wt%. Tensile strength peaked at 29.85MPa at 2wt% while the flexural strength peaked well above pure PP at 45.5MPa at 7wt%. Charcoal waste ash is possible to enhance the mechanical properties of polypropylene, suggesting its potential as a sustainable material in polymer composites.

State-of-the-Art Carbon-Nanotubes-Reinforced Copper-Based Composites: The Interface Design of CNTs and Cu Matrix

Carbon nanotubes (CNTs)-reinforced copper-based composites (CNT/Cu) have been extensively investigated due to their exceptional theoretical electrical, thermal, and mechanical properties. However, the actual performance of these composites has consistently fallen short of theoretical expectations. This discrepancy primarily arises from the inability to achieve direct chemical bonding between copper and carbon nanotubes or to alloy them effectively. Consequently, this leads to interference in electron and phonon transmission at the interface between the two materials, adversely affecting their electrical and thermal conductivity as well as other properties. In recent years, research has increasingly focused on optimizing and regulating the interfacial interactions between carbon nanotubes and the copper matrix to enhance overall performance while also exploring potential applications. This article reviews recent advancements from an interface regulation perspective, summarizing typical interfacial characteristics such as physical interfaces, chemical bonding, and metallurgical bonding along with their respective preparation methods and effects on performance enhancement. Furthermore, a novel microstructural design of CNT/Cu is put forward, where amorphous CNTs (aCNTs) were utilized as the reinforcing phase to form a nanoscale networked composite interface. This not only enables Cu to adhere to the aCNTs’ sidewall but also fills the sidewall within them, with the aim of significantly strengthening the interfacial bonding strength of CNT/Cu and achieving comprehensive improvement of the composite material properties.