Conventional Hand Lay-up Technique Research Articles

Analysis and prediction of erosion behavior of epoxy composites using statistical and machine learning techniques

This work reports on the application of different machine learning (ML) techniques and statistical methods to analyze and predict the erosion wear performance of ramie fiber-reinforced epoxy composites. These composites, fabricated by conventional hand layup technique, are subjected to high-temperature erosion wear following a test schedule based on the design-of-experiments. The experimental database is used to determine the relative significance and contribution of individual parameter on the erosion wear rate using the analysis of variance. It suggests the impact velocity as the most significant factor contributing 81.2%, followed by impingement angle (13.56%), erodent temperature (0.06%) and stand-off distance (0.05%) to the wear rate. The data generated from experimentation are further processed to predict the erosion performance of the composites with a ML approach following four different algorithms such as support vector machine, decision tree, random forest and gradient boosting machine (GBM). The feature scores for different parameters in the above models are also evaluated to ascertain the contribution of each parameter, which consequently revealed that impact velocity and impingement angle with respective mean feature scores of 0.7538 and 0.1824 have maximum influence on the erosion rate. The performances of four different ML models are compared on the basis of their coefficient of determination (R2 value). It is found that the GBM outperforms other models with a R2 value as high as 0.9543 and has thus emerged as the best-performing prediction model. The possible mechanisms causing the wear loss are identified using electron microscopy.

Experimental Investigation of Mechanical and Physical Properties on Epoxy Resin with Wood Timber for Furniture Application

ABSTRACT Composites are attracting the attention of researchers nowadays because of their strength-to-stiffness ratio. The development of wood particle composites reinforced for practical purposes has been successfully attempted. This paper focuses on the application of an epoxy/hardener ratio with wood particle-reinforced polymers to develop high-strength wood composites. The percentage of wood particles in the composition varied as follows: 5, 15, and 25 wt%, with epoxy/hardener ratios of 5:0.3, 10:1, and 5:0.8. Appropriate surface modifications were made by different treatments with 0.6, 0.8, and 1 g of NaOH in 10 liters of distilled water and 0.2% KMnO4 for better adhesion of particles and epoxy. Flexural strength, impact strength, water absorption, and SEM were investigated. Nine experiments were investigated based on the Taguchi orthogonal array blend design. The composite was successfully fabricated using the conventional hand lay-up technique. The highest mean S/N ratio considered was found for wood content composition (15%), epoxy resin to hardener ratio (10%), and NaOH (1%), i.e. the main factors affecting the mean flexural and impact strength were the wood particle contents in the matrix. Water absorption was investigated. Water absorption was found to increase with wood particle content.

Development and mechanical characterization of cenosphere-reinforced CFRP and natural rubber core sandwich composite

Driven by the growing concern for environmental sustainability, there is an increasing need to explore innovative approaches for repurposing industrial waste materials. This study focuses on investigating the potential uses and challenges associated with cenosphere, a waste product derived from coal combustion in thermal power plants. Typically regarded as waste, cenosphere offers an opportunity to contribute to sustainability efforts. The objective of this research is to evaluate the influence of cenosphere, a ceramic-rich industrial waste, on the mechanical properties of woven CFRP-Rubber-CFRP (Carbon fibre-reinforced polymers) sandwich composites. The composite specimens were fabricated using the conventional hand lay-up technique, incorporating different weight percentages (5, 10, 15, and 20 wt.%) of cenosphere as a particulate filler. Tensile, flexural, and impact testing were conducted according to ASTM standards to assess the impact of the filler content on the mechanical properties. The results demonstrate that the inclusion of approximately 15% by weight of discarded cenosphere significantly enhances the tensile strength, flexural strength, interlaminar shear strength (ILSS), and impact strength of the sandwich composites, yielding improvements of approximately 1.6, 1.56, 2.06, and 1.85 times, respectively, compared to unfilled composites. Microscopic analysis of the composites reveals a well-dispersed cenosphere distribution within the matrix, contributing to the notable enhancement in overall strength characteristics.

Assessment of compressive and wear performance of waste marble powder and short banana fiber reinforced epoxy composites

In the research work, conventional hand layup technique will be adopted to fabricate waste marble powder (WMP) filled banana fiber (BF) with epoxy resin composite for analysis of mechanical characteristics like compressive stress, compressive strain, and wear rate. The waste marble powder weight percentage will be varied from 0 wt% to 20 wt% at 5 wt% interval. The chopped banana fiber weight percentage will be varied from 15 wt% to 35 wt% at 5 wt% interval. The epoxy resin weight percentage will be kept as 65 wt% for all samples. The specimens for compression and wear test will be prepared as per ASTM standards. The maximum compressive stress, compressive strain, and wear rate of the all composites will be evaluated through Universal Testing Machine and Pin on Disc Machine correspondingly. The outcomes from the above tests will be compared to choose the optimum filler/fiber ratio. The prepared composites will be aimed to use in packing applications.

Parametric analysis of erosion wear of sponge iron slag-filled ramie–epoxy composites using Taguchi and preference selection index methods

The present work reports on the development of a novel set of ramie–epoxy composites filled with sponge iron (SI) slag (0–30 wt.%) and on their response to solid particle erosion wear under different test conditions. SI slag is a by-product generated during the processing of SI to steel in arc or induction furnace. While these composites are fabricated using the conventional hand layup technique, the erosion tests are carried out using an air jet erosion tester following ASTM G76 test standard as per Taguchi's L27 orthogonal array. Mechanical characterization of ramie–epoxy composites suggests that the incorporation of SI slag improves their tensile strength by about 52%, flexural strength by 10% and micro-hardness by about 30%. A parametric appraisal of the erosion response carried out using Taguchi method reveals that the filler content, impact velocity and impingement angle are the most significant control factors influencing the erosion rate of these composites. The individual effects of different factors in wider ranges (impact velocity 25–125 m/s, filler content 0–30 wt.% and impingement angle 30–90°) are ascertained by conducting steady-state erosion experiments in controlled conditions. Preference selection index method, which is an effective multi-criteria decision-making tool is used to select the best candidate among all composites based on different physical, mechanical and wear test results. It is found that the composite with 30 wt.% SI slag content displays the optimal combination of properties. The worn morphologies of the eroded surfaces of the composites are studied and analyzed using electron microscopy to identify possible mechanisms causing the wear loss.

Development and characterization of titanium oxide filled ramie fiber based hybrid composites

AbstractThis investigation aims to develop and characterize a class of multi‐phase hybrid composites consisting of bi‐directional ramie fibers, epoxy resin and micro‐sized titania (TiO2) particles in different proportions. Conventional hand layup technique is followed for fabrication of these composite slabs with fixed fiber fraction but different filler loadings of 0, 10, 20, and 30 wt%. The composites are subjected to different physical, compositional, and mechanical characterization tests under controlled laboratory conditions. The microstructural features of the composites are studied using scanning electron microscopy and stereo‐microscopy. For the compositional analysis, Fourier transform‐infrared spectroscopy (FTIR) and X‐ray diffraction (XRD) technique are adopted. The functional groups present in the constituent materials are identified and so also the different phases in the composites. The different characterization tests reveal that with the incorporation of hard titania particles, the tensile, flexural, inter‐laminar shear strength, hardness, and impact strength improve. Similarly, the density and moisture absorption behavior are also found to be greatly affected by the inclusion of fillers. Armed with reasonably good mechanical properties and improved hardness, these epoxy‐ramie composites filled with titania micro‐particles may possibly find applications as functional materials in potential areas like wear prone situations.Highlights Hybridization of ramie‐epoxy composite by additional reinforcement of TiO2. Physical properties of the composites are affected by the inclusion of fillers. Mechanical properties of composites improved with filler content. The developed composites can be used for wear resistant applications.

Investigation on the mechanical properties of natural composites made with Indian almond fiber and neem seed particulates

Features such as environment friendly and low cost attract the industrialists toward natural composites. The utilization of agricultural wastes in the manufacturing of natural composites expands its usage in several industrial applications. Hence, the research on the extensive usage of agricultural wastes is still required. Consequently, in this research, an attempt has been made to fabricate the natural composites using the agricultural wastes like Indian almond fruit and neem seed. Indian almond fiber was extracted from the fruit and neem seed were converted into powder form. Composite was prepared by conventional hand layup technique. The fiber quantity was kept as constant and neem seed particle (NSP) volume fractions were varied from 2.5 to 10 wt%. Mechanical tests like tensile, flexural, impact and hardness were determined. Results indicated that the fiber and NSP showed good reinforcement effect. The Indian almond composite (IAC) with 7.5 wt% NSP, that is, IAC/7.5 wt% NSP composite, exhibited the better mechanical properties. Further, the IAC/10 wt% NSP composite displayed the less water absorption and least degradation. This study suggests that the IAC/7.5 wt% NSP composite could be used in industrial applications due to its good mechanical properties.

Mechanical and Thermal Adsorption Actions on Epoxy Hybrid Composite Layered with Various Sequences of Alkali-Treated Jute and Carbon Fibre

Structural applications are accomplished by using a lightweight epoxy matrix bonded with natural jute fibre/synthetic carbon fibre to enhance the physical, mechanical, and thermal properties obtained by different sequences of alkali-treated jute fibre (J.F.)/carbon fibre (C.F.) through conventional hand layup technique. The sequences of the sample are named as H1, H2, H3, and H4 layers of JF/JF/JF/JF, CF/CF/CF/CF, JF/CF/CF/JF, and CF/JF/JF/CF. Influences of JF/CF on physical, mechanical, and thermal adsorption properties of the epoxy composite are evaluated and compared. The mechanical tensile performance of the jute fibre-covered (JF/CF/CF/JF) composite H3 sample is augmented by 29% compared to the H4 sample. Similarly, the CF/JF/JF/CF combinations exhibited a higher impact strength of 129.71 KJ/m2. The maximum hardness of 47.12Hv was found on the four-layered carbon fibre. The thermal adsorption actions on developed composites are evaluated by thermogravimetric apparatus (TGA). It is confirmed that the presence of JF/CF in epoxy composites can endure stability at a higher temperature.

Effect of fiber orientation on the mechanical properties of unidirectional basalt fiber reinforced polymer matrix composites

Polymer matrix composite materials have attracted the researchers over a period due to its superior specific strength, compared to conventional materials. Bio-based fibers have started to emerge rapidly for industrial components, encompassing the technological/scientific aspects and the economic, environmental and social issues. Amongst the variety of bio-based fibers, basalt fiber occupies a prominent position, due to its overall production and unique chemistry-related features. It is chemically inert and non-reactive. In the present investigation, unidirectional basalt fiber of 240GSM at different orientations is added as reinforcement with a fixed weight percentage of 55% to LY556-HY951 epoxy-hardener combination as matrix. Fabrication is carried out by conventional hand lay-up technique. Mechanical characterization such as, tensile, flexural, hardness and inter laminar shear strength tests are conducted for the fabricated material. Morphological studies are conducted using scanning electron microscope (SEM) to visualize the fiber pull out, presence of voids and matrix-fiber adhesion characteristics. From the results obtained, it can be concluded that the highest strengths are obtained for laminates with zero-degree fiber orientation, which makes it suitable to be used for engineering, structural and biomedical applications

Influence of nano-silica on mechanical properties of Indian almond fiber reinforced hybrid epoxy composites

ABSTRACT Natural fiber reinforced composites are useful in engineering applications as energy saving material due to their light weight. However, the lower mechanical properties limit it service compared to conventional material. Hence, the purpose of this study is to improve the mechanical properties of the natural fiber composites using nano-silica particles. Indian almond fiber-based epoxy composite was manufactured with different quantity of nano-silica. Totally, five materials were fabricated namely E (Epoxy), EI (Epoxy/Indian almond), EIS1 (Epoxy/Indian almond/0.5 wt% silica), EIS2 (Epoxy/Indian almond/1 wt% silica), and EIS3 (Epoxy/Indian almond/2 wt% silica) by conventional hand layup technique. Mechanical properties such as tensile, flexural, impact, and hardness were tested. Further, water absorption behavior of the materials was analyzed to understand the dimensional stability of the material. Results showed that EIS3 composite exhibited the higher tensile strength of 77 MPa, flexural strength of 109 MPa, impact strength of 4.31 KJ/m2, and hardness of 93 shore D. Mechanical properties of EIS3 composites were improved due to the reinforcing effect of Indian almond fiber (40 wt%) and nano-silica (2 wt%). Water absorption study showed that the EI composite displayed the maximum water absorption of 14.6% at the soaking time of 6 hours due to hydrophilic tendency of fiber. This investigation concludes that EIS3 composite could be applicable in engineering applications for constructional work owing to its improved performance.

Effect of hybrid fillers of Mg–Al layered double hydroxide and nanoclay on the mechanical behavior and formability of glass laminate AA5052‐reinforced epoxy composites

AbstractThis research work investigates the influence of hybrid particulate fillers, Mg–Al layered double hydroxide (LDH), and nanoclay (NC), on the mechanical properties and formability of glass laminate AA5052 epoxy composites (GLARE). The composite laminates were prepared by varying the weight percentage (i.e., 3, 4, and 5 wt%) of the hybrid fillers in the epoxy resin. The conventional hand layup technique was utilized for the fabrication of the laminates. The tensile test samples were prepared in different orientations with respect to the rolling direction (i.e., 0°, 45°, and 90°) to address their anisotropic nature. The flexural, impact, lap shear, and formability tests were conducted as per ASTM and IS standards. The Erichsen cupping test was performed to study the formability of the composite laminates. For each test, the results were compared with that of the laminates containing individual LDH filler, NC filler, and no filler material. The results showed that the composite laminate with 5 wt% of LDH + NC hybrid filler exhibited enhanced tensile properties, impact energy, and lap shear strength while the laminate of 4 wt% LDH + NC filler possessed better flexural properties. The formability of the composite laminates with hybrid LDH + NC fillers was observed to be lower than that of the laminates with individual filler materials and laminate without any filler. The variation observed in the test results was justified by investigating the failure mechanism of the composite laminates using a scanning electron microscope.

A review on Graphene Reinforced Composites for Ballistic applications

The review paper emphasizes mainly on the hybridization of coir fiber and spider silk with carbon fiber and different percentage compositions of graphene, with an ultimate aim as to how the strength of these hybridized composites can contribute in the fields of material and manufacturing engineering. Firstly, there is an analysis of different properties of coir, carbon fibers, graphene and spider silk. Secondly, there is an analysis of the ballistic test performed on the specimens. In this review, some very basic yet important information is collected and discussed which will help the future researchers in the preparation of hybrid composites involving graphene. Being a natural fiber, the bristle coir fibers are pre-treated with alkali (NaOH) and then acidic treatment is done to remove the excess alkali. After the fibers become neutral, permanganate treatment is done. In case of spider silk, no pre-treatment is done. These fibers are reinforced with epoxy and different weight percentage of graphene (1wt%, 2wt%, 4wt%, 6wt %). Carbon fibre is incorporated in between using conventional hand layup technique. The epoxy and graphene mixture is sonicated to make sure that a uniform and good mixture is obtained. The review facilitates to perform ballistic test on the samples as the results from this test can substantiate to deliver a vital improvement in the field of material selection for body armors.

Mechanical Characterization Of Mmt Nano Clay/Epoxy/ Basalt Fiber Composites

The importance of composite fibers have been rapidly increasing since the inception of its discovery, in almost every engineering field. They possess beneficial properties such as low weight, high strength, highly resistive towards corrosion which makes them unique. The objective of present study is to fabricate composite using epoxy as polymer and basalt fiber as reinforcement and to investigate the influence of dispersing MMT Nano clay (Montmorillonite Nano-clay) in polymer. Conventional hand lay-up technique was used for the fabrication of composite laminate. The bi-directional basalt fiber was used as reinforcement and epoxy was taken as matrix material. Mechanical Characterization of MMT Nano clay/epoxy/basalt fiber composites was carried out for tests such as tensile, flexural and impact test, the results showed that the laminate had comprehensible properties, concluding usage of composite material is more beneficial and cost effective than conventional materials in many ways.

An investigation on dynamic mechanical properties of hybrid composite materials

In recent times, usage of Composite materials is one of the methods to achieve cost effectiveness of a product. In the current research it is intended to characterize a composite material for the usage in bumper reinforcement – automotive application. Materials chosen for the investigation are a natural fiber (JUTE), synthetic fiber (E - GLASS) and resin (EPOXY). Composites are casted by conventional hand lay-up technique cured at room temperature. Further tailored to required dimensions and finally tested for dynamic mechanical properties such as natural frequency by Fast Fourier Transform analyzer (FFT). It can be concluded that, as the percentage of jute increases and E-glass decreases for lower percentage of Epoxy the stiffness of composite decreases resulting in increased vibration levels. The tests are repeated for different composition of resin which also shows similar trend and change in the value of natural frequencies.

Experimental and Numerical Study on Free Vibration of Multiwall Carbon Nanotube Reinforced Composite Plates

The effects of different percentages of multiwall carbon nanotube (MWCNT) on natural frequencies of polymer composite plates of varying edge-to-thickness ratio, aspect ratio and boundary conditions at ambient temperature are investigated experimentally and numerically. Conventional hand lay-up technique is used to prepare the MWCNT polymer composite plates with different percentages of carbon nanotubes (CNTs) mixed to the polymer. The elastic properties are determined experimentally by conducting uniaxial tensile test in the universal testing machine INSTRON 8862 as per ASTM D-3039. A set of experiments were conducted for the natural frequencies of vibration of MWCNT composite plates using the Bruel and Kjaer Fast Fourier Transform (FFT) analyzer with pulse platform. Detailed parametric studies are carried out to determine the effect of weight fraction of CNTs, aspect ratios, edge-to-thickness ratios and boundary conditions on the natural frequency of composite plates. Numerical solutions were obtained by the commercial finite element method (FEM) package ABAQUS. A simulation model is developed using the same geometrical and material properties determined experimentally from which the frequency responses are obtained. The simulation results are found to be consistent with the experimental ones. The results obtained showed an increase in elastic properties and natural frequencies up to 0.3 wt.% of MWCNT and decrease thereafter for all cases due to agglomeration of CNT in the polymer matrix. The morphology and dispersion of the CNTs in composites at micro level are investigated by using scanning electron microscopy (SEM) to further corroborate the behavior of specimens.

Statistical analysis and investigation of tensile test data of coir composites reinforced with graphene, epoxy and carbon fibre

A successful attempt has been made to develop coir fibre composites reinforced with graphene, epoxy and carbon fibre. The carbon fibres were arranged in an intercalated manner, which is similar to the coir fibres. The percentage composition of graphene was varied as 1, 2, 4 and 6% by weight of the holding matrix. Suitable surface modifications were done by treating natural fibres by 5% NaOH and 0.3% KMnO4 for better adhesion of fibre and epoxy resin. Sonication and cetyl trimethyl ammonium bromide treatments were also done to achieve the fine scattering of graphene in the epoxy matrix in order to achieve better mechanical behaviour. Moulds were made as per D638 American Society for Testing and Materials (ASTM) standards. The treated fibres were then arranged in the mould by the conventional hand layup technique. Tensile testing was carried out to determine the mechanical properties of the composites. Two-way analysis of variance was used as a statistical tool to find the effect of parameters such as ‘Percentage composition of graphene’ and ‘Type of mould’ on the modulus of the composites. Fourier transform infrared spectroscopy was conducted to determine the interferential adhesion and homogeneous distribution of fibres in the composite matrix. At last, field emission scanning electron microscopy analyses were also done to the specimens before and after tensile testing to determine the morphology of different entities present in the composites.

The Influence of Moisture Absorption on the Mechanical and Thermal Properties of Chemically Treated DPL Reinforced Hybrid Composite

Moisture absorption of natural fiber-based composites is one of the major problems in outdoor applications. The present study deals with the effect of moisture absorption on mechanical and thermal properties of unmodified/modified Date Palm Leaf (DPL) with glass fiber-based hybrid composites. Natural fibers were modified with alkaline treatment to improve fiber and matrix bonding. Conventional hand lay-up technique is used to fabricate the composites with varying different wt.% of treated and untreated short DPL with constant wt.% of glass fiber and prepared with random oriented manner. The combine effect of hydrophilic and hydrophobic nature find out as the study based upon the natural with synthetic fiber hybrid composites. Mechanical behaviour of the epoxy-based hybrid composites were characterized by using tensile, flexural and hardness test. The results revealed that significant improvement in mechanical properties by the addition of different weight percentage of modified DPL. Different thermal properties of the composites were described by using Thermo Gravimetric Analyzer (TGA) and Differential Scanning Calorimetric (DSC). Morphological investigation was carried out to by using scanning electron microscope. All the properties of untreated natural fiber reinforced composites were mostly affected by the influence of water absorption as compared with chemically treated based composites.

Testing and Evaluation of Tensile and Impact Strength of Neem/Banyan Fiber-Reinforced Hybrid Composite

Abstract Natural fiber-reinforced hybrid composites are prime focus materials for numerous engineering applications. In this research work, chopped neem (Azadirachta indica) fibers and bidirectional banyan (Ficus benghalensis) woven fabric-reinforced epoxy hybrid composites were fabricated using the conventional hand lay-up technique. Two fibers, namely chopped neem fiber and woven banyan fiber, were stacked in three different sequences. The weight fraction of these two fibers was varied to quantify the strength of the hybrid composite. The mechanical properties, such as tensile, compression, and impact tests, were carried out to quantify the effect of the fiber weight fraction and the stacking sequence of fiber on the strength of the hybrid composite. The increase in 9 % woven banyan fiber weight fraction has a positive influence on the tensile and compressive strengths of the natural fiber-reinforced hybrid composites. Further, the stacking sequence of these two fibers has significant influence on the compressive strength of the hybrid composites. The impact energy absorption capacity of the hybrid composite is more significantly increased with an increase in the 9 % chopped neem fiber weight fraction than with an increase in the banyan fiber weight fraction. The scanning electron microscopy surface morphological analysis revealed the dominant mode of failure in the hybrid composites.

Water and brine absorption capacity of epoxy based glass fiber composite modified with CaCO3–Al2O3–MgO–TiO2/CuO filler materials

Glass fiber reinforced composite materials have versatile engineering applications and superior performance for its various level of properties. Different fillers are mixed with the composite materials to enhance product performance. However, improvements on physical properties of this class of materials are still under research for different applications. In this work, with a fixed weight percentage of plain woven glass fiber reinforcement and epoxy composites added with four different types of fillers, such as Calcium Carbonate (CaCO3), Aluminum Oxide (Al2O3), Magnesium Oxide (MgO) and Titanium Oxide (TiO2) or Copper Oxide (CuO) at different weight ratios (5, 10 and 15 gm) are studied. The composite specimens required for different tests are fabricated in conventional hand lay-up technique followed by light compression molding process as per ASTM standards. These composites are investigated for water and brine solution absorption capacity and significant improvement is observed in case of the composite made of CuO than that of the composite made of TiO2. FTIR, TGA and SEM are also characterized.

Mechanical Behaviour of Areca Nut, Sunn Hemp Natural Fibers and E Glass Fibers Reinforced With Epoxy Composites

In this paper, tensile behaviour of the natural fiber composites such as the areca nut composites and the sunn hemp composites were determined. The fibers were arranged in different orientations such as the uniaxial, biaxial and the criss-cross arrangements. For both the types of fiber composites, specimens were made with and without the incorporation of E-glass fibers. Comparisons were done on the basis of fiber orientation, E-glass fibers incorporation and the type of natural fiber used. Initially, the fibers were treated with alkali, i.e. Sodium hydroxide (NaOH) in order to get better bonding at the fiber-matrix interface. The conventional hand lay-up technique followed by the soft compression molding technique was carried out for fabricating the composite specimens. It was inferred from the results that the tensile strength was more for uniaxial arrangement and the least for biaxial arrangement in case of both the fibers. Further, for both the fibers, E-glass fiber incorporation increased the tensile strength as compared to the non-incorporated E-glass fiber composites. Also, sunn hemp composites showed better tensile strength than areca nut composites. The research suggested that the areca nut and sunn hemp composites were assets to many potential applications that did not require very high load bearing capabilities. These examined composites can be considered as very reliable materials for fabrication of lightweight materials used in automobile industry, packaging materials, medical field, etc.