Reinforced Polymer Matrix Composites Research Articles

Application of Fiber Made from Bark of Salak (Salacca Zalacca) Tree as Reinforcement in Polymer Matrix Composites

<p class="02abstracttext">Although Indonesia is abundant supply of salak (Salacca zalacca) fruit, bark of salak is not yet advanced utilized. This work therefore chracterized its fiber and process it into polymer matrix composites. The study was conducted using varied chemical treatments. Delignification using NaOH solution with concentration of 1%, 5%, 10% with 3 hours immersion time. Bleaching treatment was using H<sub>2</sub>O<sub>2</sub> media with varied immersion time at 30, 60 and 90 minutes. Tensile tests, impact tests, microscopic image test using scanning electron microscopy (SEM) and chemical composition test using fourier-transform infra-red (FTIR) spectroscopy were carried out in this work. This work showed that optimal delignification treatment can be found when 5% NaOH concentration was used. The corresponding ultimate tensile strength and impact strength were 25.47 MPa and 11.95 kJ/m<sup>2</sup>, respectively. The optimal bleaching treatment was 90 minutes immersion. The results of SEM image analysis showed that the salak midrib fiber composite without treatment has a lousy interface. Meanwhile, fiber with delignification treatment only has reasonable good interface and fiber with delignation treatment followed by bleaching treatment has excellent interface. FTIR test results showed that the salak midrib fiber composite without treatment had a cellulose component although hemicellulose and lignin levels still dominated. The delignification treatment had succesfully broken the lignin-specific C = O bond but still could not eliminated hemicellulose and lignin bond. In comparison, bleaching treatment reduced intensity of OH intensity, CH and CO which are typical hemicellulose and lignin functional groups. Based on the results of the study, salak midrib fiber with delignification chemical treatment using 5% NaOH for 3 hours followed by bleaching treatment using 2% H<sub>2</sub>O<sub>2</sub> for 90 minutes was the best treatment.</p>

Artificial neural networks and phenomenological degradation models for fatigue damage tracking and life prediction in laser induced graphene interlayered fiberglass composites

The mechanical properties of fiber reinforced polymer matrix composites are known to gradually deteriorate as fatigue damage accumulates under cyclic loading conditions. While the steady degradation in elastic stiffness throughout fatigue life is a well-established and studied concept, it remains difficult to continuously monitor such structural changes during the service life of many dynamic engineering systems where composite materials are subjected to random and unexpected loading conditions. Recently, laser induced graphene (LIG) has been demonstrated to be a reliable, in-situ strain sensing and damage detection component in fiberglass composites under both quasi-static and dynamic loading conditions. This work investigates the potential of exploiting the piezoresistive properties of LIG interlayered fiberglass composites in order to formulate cumulative damage parameters and predict both damage progression and fatigue life using artificial neural networks (ANNs) and conventional phenomenological models. The LIG interlayered fiberglass composites are subjected to tension–tension fatigue loading, while changes in their elastic stiffness and electrical resistance are monitored through passive measurements. Damage parameters that are defined according to changes in electrical resistance are found to be capable of accurately describing damage progression in LIG interlayered fiberglass composites throughout fatigue life, as they display similar trends to those based on changes in elastic stiffness. These damage parameters are then exploited for predicting the fatigue life and future damage state of fiberglass composites using both trained ANNs and phenomenological degradation and accumulation models in both specimen-to-specimen and cycle-to-cycle schemes. When used in a specimen-to-specimen scheme, the predictions of a two-layer Bayesian regularized ANN with 40 neurons in each layer are found to be at least 60% more accurate than those of phenomenological degradation models, displaying R 2 values greater than 0.98 and root mean square error (RMSE) values smaller than 10−3. A two-layer Bayesian regularized ANN with 25 neurons in each layer is also found to yield accurate predictions when used in a cycle-to-cycle scheme, displaying R 2 values greater than 0.99 and RMSE values smaller than 2 × 10−4 once more than 30% of the initial measurements are used as inputs. The final results confirm that piezoresistive LIG interlayers are a promising tool for achieving accurate and continuous fatigue life predictions in multifunctional composite structures, specifically when coupled with machine learning algorithms such as ANNs.

X-ray computer tomography (XCT) of fatigue damage in laser-machined versus milled carbon fiber reinforced polymer matrix composites

Remote laser beam cutting is a non-contact, tool-wear-free cutting technology that guarantees consistent cutting quality for fiber-reinforced polymers with high efficiency. Since it is a thermal process, a heat-affected zone (HAZ) inevitably occurs at the edge of the cut. Within this HAZ the original material condition is changed locally, which influences the mechanical behavior of the component. In this paper, we have investigated the effect of HAZ on fatigue behavior, for the first time, using a high-resolution X-ray Computed Tomography (XCT) for carbon fiber reinforced polymer (CFRP). The investigation methodology allows non-destructive diagnostics of the HAZ. The laser-cut materials were compared to those machined by conventional milling. The quantitative damage mechanisms, in terms of delaminations, transverse cracks, etc., were investigated and correlated to the laser and milled processes.

Features of nonlinear in-plane shear deformation of a unidirectional and orthogonally reinforced polymer sheets of composite materials

A comparative analysis of typical stress-strain diagrams obtained for in-plain shear of the 25 unidirectional and cross-ply reinforced polymer matrix composites under quasi-static loading was carried out. Three of them were tested in the framework of this study, and the experimental data on other materials were taken from the literature. The analysis of the generalized shear-strength curves showed that most of the tested materials exhibit the similar deformation pattern depending on their initial shear modulus: a linear section is observed at the beginning of loading, whereas further increase of the load decreases the slope of the curve reaching the minimum in the failure point. For the three parameters (end point the linear part, maximum reduced deviation of the diagram, tangent shear modulus at the failure point) characterizing the individual features of the presented stress-strain diagrams, approximating their dependences on the value of the reduced initial shear modulus are obtained. At the characteristic points of the deformation diagrams, boundary conditions are determined that can be used to find the parameters of the approximating functions. A condition is proposed for determination of the end point of the linear section on the experimental stress-strain curve, according to which the maximum deviation between the experimental and calculated (according to Hooke’s law) values of the shear stress in this section is no more than 1%, thus ensuring rather high accuracy of approximation on the linear section of the diagram. The results of this study are recommended to use when developing universal and relatively simple in structure approximating functions that take into account the characteristic properties of the experimental curves of deformation of polymer composite materials under in-plane shear of the sheet. The minimum set of experimental data is required to determine the parameters of these functions.

A Review on Waste-wood Reinforced Polymer Matrix Composites for Sustainable Development

This study reviews the various techniques used in the preparation and processing of waste-wood fibre/particle reinforced polymer matrix composite with special interests on mechanical and structural applications. Polymer composite materials are being used in a wide range of structural applications such as construction, safety wears, aerospace and automotive industries owing to their lightweight, high specific stiffness and strength. A number of materials are being used ranging from lower performance of glass fibre/polyester used in small sail boats and domestic products to high performance of carbon fibre/epoxy systems used in military aircraft and spacecraft. In recent years, many studies have been dedicated to utilize organic fillers such as coconut shell, coir, wood, pineapple leaf, cow bone, palm kernel shell, rice husk. As fillers in order to replace synthetic fillers through utilization of natural fillers or reinforcement in thermoplastic and thermoset polymer composites in an attempt to minimize the cost, manage waste-wood, increase productivity and enhance mechanical properties of composites. Waste-wood as reinforcing fillers in plastics, in place of the previously used inorganic substances and synthetic fibres, offer a major benefit in terms of environmental protection. The benefits offered by waste-wood over synthetic fibres are low densities, non-abrasive, non-toxic, high stiffness and specific properties.

Studies on Mechanical properties of hybrid fiber reinforced polymer matrix composites

Composite fibers are becoming one of the inevitable sources, the inculcation of synthetic fibers and natural fibers hold a pivotal position in the engineering technologies. The process of combining composites without reduction in their properties like mechanical and physical have significantly led to increase in the quality of the product. Some of the process that can be done pertinent towards the polymers are tensile test, impact test, shear test, etc. To synthesize the component, hand layup process is been implemented in this process. The composition of components that include jute, hemp, basalt, glass and epoxy resin which when added with SiC will also be providing superior properties.

Effect of Different Fibers Loading on Palm and Aramid Fiber Reinforced Hybrid Epoxy Composite

ABSTRACT In this present research, palm (Trachycarpus fortunei) and aramid fiber reinforced epoxy composite is fabricated by hand lay-up technique with equal fiber ratio (Palm:Aramid = 1:1) and fiber loading constituting of 0, 5, 10 and 15 wt.% fiber, where palm acted as natural fiber and aramid acted as synthetic fiber. The use of bio fibers as reinforcement in polymer matrix composites is thought to have better prospects in terms of showing high earmarked properties such as light in weight, lowest density, less costly, environmental conciliation, have sustained aspect for effective transfer of stress, etc. Mainly, the effect of fibre loading on mechanical properties (tensile, flexural, impact, hardness) and physical property (water absorption) is assessed in this research work. Experiments are directed according to ASTM standards for evaluating mechanical and physical properties. Surface morphological analysis is conducted through field emission scanning electron microscopy (FESEM) for observing the fiber–matrix bonding on the tensile fracture surface. After evaluation, it is found that flexural, impact, hardness properties along with water absorption percentage have shown incremental behaviour with the enhancement of fiber loading. On the other hand, tensile properties have shown dissimilar performance with the enhancement of fiber loading.

Manufacturing and Characterization of Epoxy Matrix Hybrid Nanocomposite

Advanced recent materials such as continuous reinforced polymer matrix composites provide important enhancements to a variety of structures (especially resistance to breakage), compared to their bulk, monolithic counterparts. In this research work, flexural strength and tensile or mode I fracture resistance of the hybrid polymer composite, and a detailed investigation on the processing (using Hand Lay Up method) of reinforced, unidirectional hybrid composite has been extensively discussed. Microstructral studies have also been carried out to know the material fracture behaviour and its effect on the orientation of notch. The obtained results are critically examined and discussed elaborately to find: (i) orientation of fiber and its effect on the anisotropy in flexural strength and fracture behaviour, (ii) effect of notch root radii on the conditional fracture toughness and concurrence to linear elastic controlled fracture, and (iii) the nature of J integral resistance curves. The effectiveness of the conventionally used hand layup technique is amply demonstrated by the achievement of significantly higher strength (flexural) values and also, a very importantly combination of strength and fracture resistance; qualifying the composite thus manufactured to declare this hybrid composite as a novel composite material with high specific strength when compared with other polymer matrix composite (PMCs) for a wide group of aeronautical and aerospace structural applications.

Investigation of the suitability of fiber reinforced polymer matrix composites for facilities operating in marine environment

This paper is related to the production and investigation of the structure, the mechanical and physicochemical properties of two kinds of fibre reinforced polymer matrix composites in order to assess their suitability as materials used in equipment operating in marine environment. The one of the investigated composites has a polyester resin matrix and a reinforcement phase of six-layer fibreglass, and the other one has a vinylester resin matrix and a reinforcement phase which is a combination of three-layer fibreglass and three-layer biaxial fibreglass. A comparative analysis has been made of the relative weight, tensile strength and bending strength of the two types of composite materials.

Investigation on the Effect of Nano Fillers on Tensile Property of Neem Fiber Composite Fabricated by Vacuum Infused Molding Technique

Now a days, natural fiber based polymer composites are having more attention because of it is good mechanical properties and environment friendly. The foremost aim of this investigation attempt is for examine the effect of the nano-filler over the tensile properties of natural based polymer composite.. Just one nano-material is used in most of the research for the production of new composites. In this analysis, the vacuum assisted by infusion molding method uses the neem fiber and two different nano-filler materials for creating new nano infused composites. Neem fiber is chosen as a fiber and LY556 epoxy-resin is selected as polymer materials for the production of reinforced polymer matrix composites of this natural fiber material. Composites of the neem fiber based polymer composites is developed by infused the neem fiber with the nano to examine the tensile property of the neem fiber infused composite and the effect of nano-filler materials. By infusing nan-ofiller materials to build nano based natural fiber polymer composites; the average ultimate tensile strength for the polymer matrix composite is 15.5 percent.

Mechanical properties and morphological study on palm Fiber/S-Glass reinforced polymer matrix composites

This investigation examine the polymer matrix composite material prepared from 32 wt% epoxy resin LY556 and 3 wt% hardener HY951 with Palm fiber (30 wt%, 20 wt%, 10 wt%) and S-glass. Composite materials are made by reinforcing at least two materials of different properties. Hybrid Composite materials are framed by combining natural and synthetic fibers. In this study based on the physical, synthetic and mechanical properties of the chosen materials the necessary epoxy resin LY556 and hardener HY951 are picked and fabricated accordingly by using hand lay-up method. The test specimens are cut as per the ASTM standards using waterjet cutting. Different tests were conducted to assess the Mechanical properties like tensile strength, flexural strength, impact strength and hardness of the hybrid composite material. The morphological study used to identify the structure of the composite material is done by using scanning electron microscope. The elemental analysis also examined using SEM-EDX. The test results show that the specimen 1 (30 wt% palm fiber) which have the better strength, firmness, high strength to weight ratio and other mechanical properties compared to other specimens 2 (20 wt% palm fiber) and 3 (10 wt% palm fiber). The morphological properties show that the composite materials have good bonding properties. The SEM-EDX analysis show that the composite material has 49.64% carbon which is a high strength element used for structural applications.

Comparative Study of the Mechanical and Water Absorption Behaviour of Basalt Fiber Reinforced Polymer Matrix Composites with Different Epoxies as Matrix for Biomedical Applications

In comparison to conventional materials, polymer matrix composite materials have witnessed a surge in applicability due to their higher specific strength‐to‐weight ratio, abundant availability, and ease of shaping. Due to technological, economic, environmental, and societal challenges, bio‐based fibers began to emerge quickly for use in industrial components. Due to its unique chemistry‐related characteristics, basalt fiber holds a prominent position among the many bio‐based fibers. So, it could be thought of used as a replacement for some components used in the biomedical equipments. In the present investigation, plain‐woven basalt fiber at a constant percentage of 55% is added as reinforcement to three different epoxy resin‐hardener combinations such as Lapox L12‐Lapox K6, Araldite LY1564‐Aradur 22962, and Araldite LY556‐Aradur HY951 as matrix, and comparative studies are carried out. Fabrication is carried out by hand lay‐up technique. Test specimens are prepared as per the respective ASTM standards by subjecting the laminate to water jet machining. Mechanical characterization such as tensile, flexural, and density tests is conducted for the test specimen using BISS‐50 kN Universal Testing Machine (UTM). Water absorption tests are also conducted for 24 and 48 hours duration. From the results obtained, it is concluded that the highest tensile, flexural strengths are obtained for laminate L3 which used LY556 epoxy and HY951 hardener combination as matrix. Also, less rate of water absorption is seen for L3 laminate for both 24 and 48 hrs which makes it suitable for biomedical applications.

Date-Palm Fiber as a Reinforcement Filler in Polymer Composites

Natural fibers offer a great advantage of being used as a reinforcement in polymer matrix composites because of the many advantages natural fibers offer over conventional reinforcement fillers. Date palm fiber is one of the most available natural fibrous materials in the Middle Eastern region to be exploited as a fiber reinforcement in polymers. In the present work, the fibers extracted from the date palm tree trunk, branches, and leaves were used for the reinforcement of the polypropylene matrix. Electron microscopic images show excellent bonding between the fiber and matrix as no fiber pullout is observed. The thermal (heat deflection temperature) and mechanical properties (Izod impact, tensile and flexural modulus) of the composites increased with an increase in the fiber loading from 20% to 60%, which in turn resulted in excellent mechanical properties in the final product. The work has immense significance in using date palm as an easily available natural resource for a useful product.

Experimental study and characterization of glass, jute & sisal fiber reinforced polymer matrix composites

Experimental study and characterization of glass, jute & sisal fiber reinforced polymer matrix composites

Composite materials and their damage detection using AI techniques for aerospace application: A brief review

Abstract Materials for different structural and machine elements have gained importance from last two decades. With the hi-tech age, scientists are interested in specialised materials with specific properties. So, in last two decades utilization of composite materials has been rapidly increasing in order to fulfil the requirements of Aeronautical, space and nuclear sectors. Fibre reinforced polymer matrix composites gained significance role by replacing the conventional metallic materials in many aspects though they are having high performance characteristics, high specific stiffness and strength, weight saving ability, tailored into any critical structural shape, resistance to fracture and fatigue, damage tolerance and greater resistance to oxidation. Present study provides a brief review on various composites used in aeronautical engineering with focus on specific characteristics and features of composites required for aerospace structural members and their benefits.

Enhanced electrical, mechanical, and viscoelastic properties of carbon-carbon composites using carbon nanotubes coated carbon textile as reinforcement

In this research work, Carbon-carbon composites (CCCs) were fabricated via carbonization of carbon nanotubes (CNTs)-coated carbon textile (CNT-CF) reinforced polymer matrix composites (PMCs) preforms at 600, 900, 1200, and 1500 °C in a tubular furnace. To obtain CNT-CF, MWCNTs were produced radially on the surface of the nano-nickel particles plated carbon textile at 700°C using catalytic chemical vapor deposition method and C2H2 gas as a carbon source. The effects of CNT coating on carbon textiles were evaluated using FESEM, HR-TEM, XRD, Raman, TGA, and BET analysis. The effects of heat treatment temperatures on CNTs coated and uncoated PMCs manufactured using simple hand-layup method subsequently hot compressing were evaluated through XRD, FESEM, density, electrical conductivity measurement, tensile and flexural test, and viscoelastic properties using DMTA. The CNT coated CCCs obtained at 1500°C exhibited ∼ 66, 62, 83, 27, 44, 30, and 36% enhancement in electrical conductivity, storage modulus, loss modulus, tensile strength, Young’s modulus, flexural strength, and flexural modulus of CNT coated CCCs, respectively compare to uncoated CCCs. Moreover, substantial enhancement in thermal stability of PMCs and CCCs make CNT-CF as one of the competent alternate reinforcement for the fabrication of structural parts used in high-performance applications.

Investigation of Static and Dynamic Mechanical Properties of Short Palmyra Palm Leaf Stalk Fiber (PPLSF) Reinforced Polymer Composites

ABSTRACT The research work is focused toward determining the static and dynamic mechanical properties of the composites made by reinforcing untreated and alkali-treated short palmyra palm leaf stalk fibers (PPLSF) of length 3 mm, , and 10 mm in the polymer matrix. The short palmyra palm leaf stalk fiber reinforced polymer matrix composites are prepared by a compression molding method. The result illustrates that the 7 mm alkali-treated short PPLSF composite exhibited the maximum tensile strength of 45.13 ± 1.57 MPa, the flexural strength of 71.35 ± 2.57 MPa and impact strength 10.21 ± 2.13 kJ/m2. The dynamic mechanical analysis shows that the 7 mm alkali-treated short PPLSF composite has improved the storage and loss modulus compared to 3 mm and 10 mm short untreated and alkali-treated fiber composites. Further thermo-gravimetric analysis carried out for 3 mm, 7 mm, and 10 mm untreated and alkali-treated fiber-reinforced composites showed that the thermal characteristics of the composites have improved due to treatments as well due to increase in fiber length. The tensile-fractured surface of the composites is also examined with SEM to identify the mechanism of failure.

Multi Response Optimization on Machinability of SiC Waste Fillers Reinforced Polymer Matrix Composite Using Taguchi’s Coupled Grey Relational Analysis

Recycling and reutilization of industrial waste is one way to minimize land pollution to attain green environment. In this research waste SiC grinding wheel was ball milled to powder form and used as filler material to develop epoxy glass fibre composite. Hand layup assisted compression moulding was adopted to fabricate grinding wheel powder filler (1, 2, 3 wt.%) reinforced polymer matrix composite. Machinability of developed composite was studied by Abrasive water jet machining. Taguchi coupled grey relation analysis was adopted to investigate the influence of input parameter viz. transverse speed, standoff distance and water pressure over output response viz. Material Removal Rate(MRR) and Kerf Width (KW) and to attain optimal control factor. Results reveal that stand off distance and transverse speed has more influence on output response. Transverse speed of 30 mm/min; 2 mm stand-off distance; 220 bar of water pressure is the optimal parameter attain higher MRR and lower KW.

Strength degradation of glass epoxy composites under hygrothermal environment

The composite structures are being used in marine applications like boat hulls, propeller blades etc. Apart from these, the composites are used as structural materials exposed to different kinds of degrading environment like temperature and relative humidity. When a fiber-reinforced composite structure is exposed to a hygrothermal environment and mechanical loads, changes in material properties are related to irreversible material strength degradation. The present study deals with the mechanical strength degradation of glass fiber reinforced polymer matrix composites when subjected to hygrothermal environment. The composite cross ply laminates were manufactured by using compression molding process with two types of curing processes cold press and hot press with a bi-directional E-Glass WR 360 as reinforcement, LY556 as resin and HY951 as hardener. The mechanical properties such as Tensile, ILSS, moisture absorption was investigated with different temperatures like 32 °C, 50 °C and 85 °C with time holding of 30 min, 60 min and 90 min in 5% of brine solution. The same mechanical properties are compared with specimens under sealed condition with unsealed condition.

Laser induced graphene interlaminar reinforcement for tough carbon fiber/epoxy composites

Poor interlaminar fracture toughness is a critical limitation in the performance of fiber reinforced polymer matrix composites over a wide range of structural applications. Recent efforts to overcome this problem have shown that the introduction of various forms of nanoscale interleaves can yield composites with improved toughness. In this work, it is demonstrated that forests of vertically aligned, laser induced graphene (LIG) can provide significant improvement to the interlaminar properties of carbon fiber reinforced composites. The conductive graphene interlayers are first synthesized using a laser induction process and then transfer printed onto carbon fiber prepregs while maintaining their out-of-plane alignment. The introduced LIG interlayers result in a significantly increased short beam shear toughness, along with a 41% and 69% increase in both initiation Mode I and pre-cracked Mode II fracture toughness of the composites, respectively. In addition, the tensile and viscoelastic properties of the carbon fiber composites are preserved post-treatment. The LIG strengthened interlaminar region exhibit failure modes that provide greater resistance to crack initiation and propagation such as cohesive failure, crack deflection and nanoscale bridging. Therefore, this work provides a simple, fast and convenient method to toughen carbon fiber reinforced composites using transferred LIG interlayers, allowing for the cost-effective and rapid fabrication of simultaneously strong and tough carbon fiber reinforced composite structures.