Use Of Composite Materials Research Articles

Compare the Properties of Composite Material by Date Leaves with Different Additives

Almost no product is made today without the use of composite materials, which have demonstrated their value over time in a variety of applications. Examples include household products, automobiles, oil and gas stations and spacecraft. Instead of using timber, leaves will be used to create a solid material. The goal of this study is to identify the distinguishing features of composite materials made from dates palm waste, as well as the overall effects on the properties when changing the mixture's proportions and the amount to which those materials are vulnerable to outside influences. It also aims to identify the best material that can be produced and used in home furnishings, manufacturing, architectural design, practical applications, and other science-related fields. This project will address the use of natural fibers from dates palm waste and some other materials to convert them into a strong, lightweight, low-cost composite material to replace wood, aluminum, synthetic fibers, and other materials in industries and uses. It will also explore the manufacturing processes, testing methods, and the outcomes of comparing it with other materials. The UHU (adhesive) matrix has the lowest hardness value compared to others. Structure tests show composites' internal composition; it plays an important role in understanding the properties of composites. The water absorption test demonstrates the duration required for composites to become saturated with water, with optimal results falling within the range of 13 to 24 hours for saturation.

Natural and synthetic hydrogels for dye removal

In recent years, dyes have been classified as recalcitrant contaminants in wastewater, exhibiting significant toxicological characteristics for flora, fauna, and humans. Various techniques are currently being studied for the remediation of water contaminated with dyes. Among the most relevant alternative technologies are bioadsorption, biocoagulation, the use of composite materials, advanced oxidation processes, etc. However, these methods have some disadvantages. Similarly, the use of hydrogels specifically designed for the treatment of contaminated water is a viable and effective alternative. This is due to their ability to adsorb large amounts of water, high porosity, and multiple active sites. This research describes dyes, their classification,toxicity, and ecotoxicity. Additionally, it presents some alternative treatments for water remediation, emphasizing the design of hydrogels based on synthetic and natural macromolecules. These hydrogels are proposed as promising materials for the removal of dyes from contaminated water. The aim of this research is to highlight synthetic and natural hydrogels as promising materials for the decontamination of water from dyes.

Recycling of Plastics in the Automotive Sector and Methods of Removing Paint for Its Revalorization: A Critical Review

The presence of plastics in the automotive industry is increasingly significant due to their lightweight nature, which contributes to reducing fuel consumption and CO2 emissions while improving versatility and mechanical properties. Polypropylene (PP) and other polyolefins are among the most commonly used materials, especially for components such as bumpers. The use of composite materials, i.e., a combination of different polymers, improves the properties through synergistic effects, thereby also improving the performance of the final product. In the automotive industry, PP reinforced with 20% talc or CaCO3 is commonly used. The mechanical recycling of polypropylene bumpers is the most common type of recycling. However, challenges arise during this process, such as the presence of impurities like paint, chemical contaminants from previous use, and polymeric impurities from different polymers mixed into the polymer matrix, among others. Paint affects both the aesthetic quality and the mechanical and intrinsic properties of the recycled material. This review aims to analyze the main methods reported in the literature, focusing on those with low environmental impact. Furthermore, these methods are classified according to their capacity, effectiveness, substrate damage, environmental hazards, and economic feasibility. It also aims to offer a comprehensive overview of the mechanical recycling of plastic waste in the automotive industry.

Characterization of Novel Cellulosic Salvadora Persica Fiber for Potentiality in Polymer Matrix Composites

ABSTRACT Natural fiber is expected to make polymer composites light and environmentally friendly. In this paper Salvadora persica natural fiber is characterized in view of its use in composite materials for the first time. Average diameter of the fiber was 250 µm and density was 1.3 g/cm3. The surface of the fiber was irregular with impurities and surface features such as shallow tubs, cell walls and lignin were revealed by Scanning Electron Microscopy (SEM). X-ray diffraction (XRD) analysis reveals Crystallinity Index (C.I) of 58% and Crystallite Size of 3.58 nm. The chemical bonds pertaining to different constituents of the natural fiber such as cellulose, hemicellulose and lignin were identified by Fourier Transform Infrared (FTIR) spectroscopic analysis. In the thermal degradation of the fiber during the Thermogravimetric analysis (TGA), three stages were identified. The maximum thermal degradation temperature (Tfinal) was determined to be 357°C. Tensile strength, Young’s modulus and percentage elongation of the fiber were 430 ± 100 MPa, 16 ± 3.9 GPa and 4.2 ± 0.91% respectively.

Influence of loading conditions on acquired AE signals in biocomposites

Composite materials are increasingly used in lightweight transportation systems and civil engineering due to increasing weight constraints and installation costs. In the case of transportation systems such as in the aerospace and automobile industries, the use of composite materials reduces the weight, which is reflected in increasing the transportable load and reducing fuel consumption, and therefore the mechanical performance of the material is a very important and desired attribute. Biocomposites reinforced with natural fibers, such as flax, are gaining attention in engineering applications due to their sustainable and mechanical properties. This paper's research was designed to investigate the AE signals at different loading conditions of V-notched biocomposite specimens. Applying different loading cases, ranging from pure tension to pure shear, provided an understanding of the material's response under diverse stress states. The multi-axial strength and failure characteristics of biocomposites are evaluated. Digital image correlation technique provided measurement of strain fields complemented with AE data. AE signals have proven effective in capturing the onset and progression of different failure sources in composite material.

On the role of temperature in the response of air-backed composites to hydrodynamic loading: An experimental study

Understanding the role of temperature in the dynamic response of composite plates is critical for naval systems operating in extreme environments like the Arctic. Despite the advantages of composite materials in improving corrosion resistance and enabling the customization of material properties to their environment, their behavior at cold temperature, especially under dynamic loading, remains elusive. This research gap hinders the effective use of composite materials in extreme environments. Here, we study the dynamic response of air-backed fiberglass epoxy plates under hydrodynamic loading at room temperature and 4∘C. By employing digital image correlation and particle image velocimetry, we investigated the interplay between fluid–structure interactions and cold temperatures. Our findings reveal the critical role of temperature in shaping the dynamic response of air-backed composites through changes in the stiffness and damping properties. At cold temperature, the plate experiences a larger (smaller) deformation in the initial (latter) phase of the dynamic response. Furthermore, we observed a pronounced coupling between the structural response and the flow physics, with peaks of the hydrodynamic loading synchronized with the peak deflections. Our results underscore the importance of considering temperature in the design of naval systems for extreme environments, providing key insights into fluid–structure interactions at cold temperature.

Modification of Sulfur Cake—Waste from Sulfuric Acid Production

In the production of sulfuric acid, sulfur cake—a waste product of the sulfur purification process—is formed in large quantities, which requires its disposal and use. For its use in composite materials, modification is necessary to convert sulfur into a polymer form. The aim of the study was to develop a method for modifying sulfur cake—a waste product of sulfuric acid production—for its disposal. Available reagents—styrene, glycerol, and oleic acid—were tested as modifiers in the work. The sample compositions consisted of 100% sulfur cake (no. 1) and its mixtures: 97% sulfur cake + 3% styrene (no. 2), 97% sulfur cake + 3% glycerol (no. 3), 97% sulfur cake + 3% oleic acid (no. 4), 95% sulfur cake + 3% styrene, 1% glycerol, and 1% oleic acid (no. 5). Modification of sulfur cake was carried out at a temperature of 140 °C for 30 min. The composition, crystal structure, and thermal properties of the samples of the original and modified sulfur cake were studied using X-ray phase and X-ray structural analyses, IR spectroscopy, differential scanning calorimetry, differential thermal and thermogravimetric analysis. The optimal modifier for sulfur cake was a mixture of styrene, glycerol, and oleic acid, which led to the formation of acetal (polyoxymethylene) and an improvement in the structure due to a decrease in the content of impurities. Modification of sulfur cake with styrene resulted in the appearance of a CAr–S bond band at 571 cm−1, and modification with oleic acid a C–S band in the region of 694 cm−1 in the IR spectra. The results of differential scanning calorimetric analysis showed an increase in the heat of fusion of sulfur by 12.45 J/g in the samples of sulfur cake modified with glycerol and styrene. Modification of sulfur cake with oleic acid and a mixture of reagents resulted in the appearance of a third peak with maxima at 244.2 and 264.0 °C, which demonstrated a significant effect of the indicated additives on the thermal behavior of the sulfur cake. Proposed schemes for modifying sulfur cake with styrene and oleic acid are presented.

Direct Composite Restorations on Permanent Teeth in the Anterior and Posterior Region - An Evidence-Based Clinical Practice Guideline - Part 1: Indications for Composite Restorations.

This German S3 clinical practice guideline offers evidence-based recommendations for the use of composite materials in direct restorations of permanent teeth. Outcomes considered were the survival rates and restoration quality and process quality of the manufacturing process. Part 1 of this two-part presentation deals with the indication classes. A systematic literature search was conducted by two methodologists using MEDLINE and the Cochrane Library via the OVID platform, including studies up to December 2021. Six PICO questions were developed to guide the search. Recommendations were formulated by a panel of dental professionals from 20 national societies and organizations based on the collected evidence. Composite materials are a viable option for the direct restoration of cavity Classes I-V and may also be used for restorations with cusp replacement, and tooth shape corrections. In the posterior region, direct composite restorations should be preferred over indirect composite inlays. For Class V restorations, composite materials can be used if adequate contamination control and adhesive technique are ensured. The guideline is the first to provide comprehensive evidence on the use of direct composite materials. However, further long-term clinical studies with comparators such as (modified) glass-ionomer cements are necessary. Regular updates will detail the future scope and limitations of direct composite restorations.

Improvement of the mechanical performance of Portland cement concretes through the addition of nanostructured carbonate material

The mechanical performance of construction materials depends on their structural integrity and therefore deficiencies cause changes in their properties or characteristics. The use of composite materials has shown that it is possible to improve properties or even create characteristics by incorporating nanostructured carbonate materials into the cementitious matrix of structural concretes. Simple concretes are characterized by low tensile strength, and this can be improved by incorporating materials with a high modulus of elasticity. The incorporation of carbonate materials such as graphene can be an alternative since such materials have tensile strength up to 100 times greater than steel. In this research, concrete specimens produced with the addition of nanostructured carbonate materials were prepared and compared with the control material (without carbonate material). Analyzing the tensile strength, it was found that concretes produced with 5% addition of carbonate materials had higher tensile strength than the control concrete (without carbonate addition) and that the addition of 2% carbonate material was not effective for improving the mechanical tensile strength. The results demonstrate the increase in the compressive strength of the specimens produced with 5% addition of carbonate material. It is concluded that the addition of carbonate materials can be an efficient alternative to solve mechanical strength problems in Portland cement concretes for structural purposes.

Cohesive failure assessment in CFRP-repaired perforated steel tubular members under bending moment

ABSTRACT The use of composite materials to repair corroded structures in the offshore industry is an evolving practice. Thus, to ensure the effectiveness of the repair, it is necessary to understand the structure’s responses under the different kinds of loads that involve its use. The repair’s success does not rely just on the laminate’s components but also on its proper adhesion to the substrate. This study examines carbon fiber laminate-repaired steel tubes that had concentrated corrosion-caused perforation damage and assesses their performance using numerical models and experiments with 1:3.5 scale samples under a pure bending moment load-scenario. To minimize stress concentration and mitigate the debonding risk, bevels were placed at the repair ends. The adhesive cohesive failure at the steel-composite interface and particularly at the ends of the repair are studied, as is the influence of the bevel geometry. Overall, the numerical model predictions lie close to the experimental result, suggesting that bevels can significantly reduce damage at the interface between steel and composites, and they can even prevent cohesive damage.

Effects of Rubber Core on the Mechanical Behaviour of the Carbon-Aramid Composite Materials Subjected to Low-Velocity Impact Loading Considering Water Absorption.

The large-scale use of composite materials reinforced with carbon-aramid hybrid fabric in various outdoor applications, which ensures increased mechanical resistance including in impact loadings, led to the need to investigate the effects of aggressive environmental factors (moisture absorption, temperature, thermal cycles, ultra-violet rays) on the variation of their mechanical properties. Since the literature is still lacking in research on this topic, this article aims to compare the low-velocity impact behaviour of two carbon-aramid hybrid composite materials (with and without rubber core) and to investigate the effects of water absorption on impact properties. The main objectives of this research were as follows: (i) the investigation of the mechanical behavior in tests for two impact energies of 25 J and 50 J; (ii) comparison of the results obtained in terms of the force, displacement, velocity, and energy related to the time; (iii) analysis of the water absorption data; (iii) low-velocity impact testing of wet specimens after saturation; (iv) comparison between the impact behaviour of the wet specimens with that of the dried ones. One of the main findings was that for the wet specimens without rubber core, absorbed impact energy was 16% less than the one recorded for dried specimens at an impact energy of 50 J. The failure modes of the dried specimens without rubber core are breakage for both carbon and aramid fibres, matrix cracks, and delamination at matrix-fibre interfaces. The degradation for the wet specimens with rubber core is much more pronounced because the decrease in the absorbed impact energy was 53.26% after 10,513 h of immersion in water and all the layers were broken.

Morphological, Thermal, and Mechanical Properties of Nanocomposites Based on Bio-Polyamide and Feather Keratin-Halloysite Nanohybrid.

One solution to comply with the strict regulations of the European Commission and reduce the environmental footprint of composites is the use of composite materials based on bio-polymers and fillers from natural resources. The aim of our work was to obtain and analyze the properties of bio-polymer nanocomposites based on bio-PA (PA) and feather keratin-halloysite nanohybrid. Keratin (KC) was mixed with halloysite (H) as such or with the treated surface under dynamic conditions, resulting in two nanohybrids: KCHM and KCHE. The homogenization of PA with the two nanohybrids was conducted using the extrusion processing process. Two types of nanocomposites, PA-KCHM and PA-KCHE, with 5 wt.% KC and 1 wt.% H were obtained. The properties were analyzed using SEM, XRD, FTIR, RAMAN, TGA, DSC, tensile/impact tests, DMA, and nanomechanical tests. The best results were obtained for PA-KCHE due to the stronger interaction between the components and the uniform dispersion of the nanohybrid in the PA matrix. Improvements in the modulus of elasticity and of the surface hardness by approx. 75% and 30%, respectively, and the resistance to scratch were obtained. These results are promising and constitute a possible alternative to synthetic polymer composites for the automotive industry.

The Effect of Natural Plant and Animal Fibres on PLA Composites Degradation Process

One of the methods to reduce long-term excessive plastic waste is the development and use of composite materials based on biodegradable polymers and natural fibres. Composites with natural fibres can exhibit very good mechanical properties, and the presence of natural fibres can significantly accelerate the degradation of the material. This study aimed to manufacture and analyse the biodegradation process of composites based on biodegradable polylactide (PLA) filled with flax and sheep wool fibres. The effect of flax and wool fibres and their content on the degradation rate compared to that of pure PLA was investigated. The degradation progress and properties of the composites were studied using an optical microscope, SEM, measurement of surface roughness, and contact angle. Additionally, flexural strength tests, a dynamic mechanical analysis (DMA), and a thermogravimetric analysis (TGA) were conducted. The effect of natural fibres on the phase transition and degree of crystallinity was analysed using differential scanning calorimetry (DSC). The results showed that PLA degrades only under UV light, but not in the composter simulating the natural environment. However, the incorporation of both types of fibres accelerated degradation of PLA/fibres composites in soil. Flax fibre composites exhibited better mechanical properties than pure PLA. For composites with wool fibres, although they showed a significant acceleration of the degradation process in the soil, their large content in the composite caused a reduction of mechanical properties. This research showed the positive effect of the addition of natural fibres on the biodegradation of PLA.

METHODS OF DRILLING MULTILATERAL WELLS FOR THE PURPOSE OF EXPLOITING MULTILAYER FIELDS

The exploitation of multi-layer fields is an urgent task for the oil and gas industry, requiring effective well drilling technologies to optimize hydrocarbon production processes. This article discusses methods for drilling multilateral wells with special emphasis on their application to the exploitation of multilayer fields. The first method discussed in the article is based on multilateral wells. This method involves drilling several shafts simultaneously from one site. It allows you to effectively develop various layers of the field, saving time and resources. An important aspect of this method is the optimal placement of the shafts, considering the geological and hydrodynamic characteristics of the field. The second method discussed in the article is the horizontal drilling method, which is actively used for the exploitation of multi-layer fields. Horizontal drilling allows the extraction of hydrocarbons from various formations, minimizing the negative impact on the environment and increasing the overall productivity of the field. The third method discussed in the article is associated with the use of modern technologies, such as multiphase drilling and the use of composite materials for casing. These innovations help improve the efficiency of drilling and production processes, increasing formation permeability and reducing well maintenance costs. In addition, the advantages and limitations of each method are discussed, as well as their applicability in different geological settings. Developing and improving multilateral well drilling techniques to exploit multilayer reservoirs is critical to effectively managing and optimizing oil and gas production, contributing to the sustainable development of the energy industry. Keywords: multi-layer fields, exploitation, multilateral wells, technology, method.

Cohesive failure analysis of carbon-fiber composite patch repair in perforated steel tubular elements

The use of composite materials to repair corroded steel structural components has expanded in the offshore oil and gas sector. The effective use of composites requires a meticulous process for choosing appropriate constituent elements. In this regard, numerical modeling is an efficient tool to better understand the impact of associated variables and enables the identification of failure causes and simulation of failure propagation. This study aims to assess the mechanical behavior of the adhesive layer at the steel - composite material interface in the repair of perforated tubular structures under bending, compression, and bending-compression. A numerical model is developed simplifying the examination and characterization of the cohesive failure mechanisms and modes occurring between the laminate patch repair and the perforated steel tubular element. The stress distribution and cohesive failure at the interface are then thoroughly investigated. The impacts of the inclusion of fillets at the patch repair ends to smoothen the transition between the composite material and the tube and the repair length are also evaluated. A Python subroutine is developed to identify the failure mode mechanisms to characterize the adhesive areas subjected to peel, shear, or mixed modes. Results suggest that pure shear mode is predominant in most of the repair locations across the three types of loading. For bending loads, the cohesive failure close to the cutout shows prominent shear mode. In the other loading conditions, the adhesive nearly fails in the vicinity of the cutouts (i.e., damage values are close to 1) in a predominant near pure shear failure mechanism. The use of fillets displaces the failure location for bending load, hence increasing the failure load level. Repairs were more extensive under Bending Moment load conditions compared to other load types. The mode ratio analysis and methodology presented in this work offer valuable tools for understanding the causes of failure modes.

Study of the characteristics of broadband matching antennas for fifth-generation mobile communications based on new composite materials

The presented research aims to analyze in detail the characteristics of broadband matching antennas specifically designed for 5G mobile communications applications, with an emphasis on innovative composite materials. The study focuses on a compact planar loop antenna designed for use on smartphones, covering the LTE/WWAN frequency bands 824 to 960 MHz, 1,710 to 2,690 MHz, and 3,300 to 3,600 MHz for full coverage of modern 5G networks. Experimental and numerical methods are used to broadly analyze the frequency range associated with 5G networks. The features of the use of composite materials in the implementation of antenna devices in 5G technologies are noted. A broadband matching circuit (BMC) with elements with lumped parameters and a reduced sensitivity invariant has been synthesized. A 3D model of the adaptive selective surface controller (SSC) was developed using CST Studio. The study results highlight the benefits of new composite materials in improving the performance of 5G antennas. This research makes a significant contribution to the development of 5G technologies by optimizing antenna design for efficient data transmission in modern mobile networks and can be a valuable resource for engineers and designers working in this field.

THE USE OF COMPOSITE MATERIALS IN PASSIVE AND ACTIVE SAFETY OF AUTOMOBILE

The article deals with the relevance of using composite materials of biological and synthetic origin in the elements of passive and active safety of the car. The topic of road safety is still topical, as cars are becoming more and more every year. The safety characteristics of vehicles should improve and environmental pollution should be reduced. To achieve these goals, various approaches of using composite materials in car body elements have been proposed. In addition to safety features, composite materials also reduce the weight of the vehicle. Such a vehicle picks up speed faster and consumes less fuel, reducing environmental pollution. Using the example of a Porsche car, parts made entirely and with carbon fiber are examined. A summary of the further use of the technology in the country and the world is given. The purpose is to show the importance of using composite materials in active and passive safety elements of the car. Method and methodology of the work. Theoretical analysis and generalization of scientific and technical literature in the context of research into the prospectivity of the use of composite materials in the automotive industry. Results. According to the conducted research and practical experience examples are given in which areas of automobile construction composite materials can be used. Scope of application of the results. The results can be used in the design and development of passive and active safety elements.

STUDY OF THE SEISMIC LOADS INFLUENCE ON LIQUID HYDROCARBON STORAGE TANKS MADE OF NANOCOMPOSITE MATERIALS

Earthquake damage to reservoirs in earthquake-prone and especially non-seismic regions could lead to serious social, economic and environmental problems, as they are used to store important liquids such as drinking and fire-fighting water, petroleum products and fertilizers. Liquid hydrocarbon storage tanks are of particular interest to the scientific community and the public. Liquid hydrocarbons are mostly flammable and explosive, poisonous and harmful, and due to leakage, they easily cause catastrophic accidents such as fire, explosion, serious threat to human life and property safety. It is relevant to study the properties of materials that allow for stable tank operation for the liquid hydrocarbons storage under natural and technogenic seismic influences conditions. The purpose of the work is to study the seismic loads impact on liquid hydrocarbon storage tanks made of nanocomposite materials to improve the environmental safety of the surrounding areas. The use of composite materials with nanoinclusions in tanks for storing environmentally hazardous liquids allows to increase the reliability of tanks under seismic loads and to extend their service life under the action of natural and technogenic influences of various origin. The results of the calculations have been shown that the use of composite materials with nanoinclusions in the steel spheres form is the best option for environmentally safe operation of tanks under seismic loads. The performed calculations allow to build the necessary systems of basic functions for the forced oscillations study, as well as the influence of surface tension and nonlinear effects on the oscillations of shells with liquid.

BEARINGLESS ROTOR SYSTEM MAIN COMPONENTS DESIGNING

Bearingless rotor system design optimizes mechanical simplicity, eliminates frictional losses typical of conventional bearing systems, and improves the overall efficiency of the rotor system. Based on the findings of the research, it is possible to determine that composite materials can be applied in order to improve the performance of the rotorcraft rotor system.A theoretical analysis of the influence of input parameters on the aerodynamic quality of the main rotor of a rotorcraft was carried out. The strength and aerodynamic quality of the designed parts were calculated using the finite element analysis method. The energy efficiency of the use of composite materials is substantiated, which will ensure better efficiency and competitiveness of the aircraft.

Uncertainty quantification for viscoelastic composite materials using time-separated stochastic mechanics

With the growing use of composite materials, the need for high-fidelity simulation techniques of the related behavior increases. One important aspect to take into account is the uncertainty of the response due to fluctuations of the material parameters of the constituent materials of the homogenized composite. This inherent randomness leads to stochastic stresses on the microscale and uncertain macroscale response. Until now, the viscoelastic response of the matrix material seriously hindered the application of efficient methods to predict the composite material behavior. In this work, a novel method based on the time-separated stochastic mechanics (TSM) is developed to address this problem. We present how the uncertainty of the microscale stresses of a representative volume element and the homogenized macroscale stresses can be approximated with a low number of deterministic finite element simulations. Quantities of interest are the expectation, standard deviation, and the probability distribution function of the stresses on micro- and macroscale. The results showcase that the TSM is able to approximate the reference results very well at a minimal fraction of the computational cost needed for Monte Carlo simulations.