Tensile Strength Of Composites Research Articles

The Facile and Efficient Fabrication of Rice Husk/poly (lactic acid) Foam Composites by Coordinated the Interface Combination and Bubble Hole Structure

The possibility of agricultural-forestry waste (rice husks) and biodegradable plastics (poly(lactic acid)) being used to produce ecologically friendly foam composite was discussed in this work. The effects of different material parameters (the dosage of PLA-g-MAH, type and content of chemical foaming agent) on the microstructure and physical properties of composite were investigated. PLA-g-MAH promoted the chemical grafting between cellulose and PLA, and made the structure denser, thus improving the interface compatibility of the two phases and resulting in good thermal stability, high tensile strength (6.99 MPa) and bending strength (28.85 MPa) of composites. Furthermore, the properties of rice husk/PLA foam composite prepared by two kinds of foaming agents (endothermic and exothermic) were characterized. The addition of fiber limited the growth of pores, which provided better dimensional stability and narrower pore size distribution, made the interface of the composite bond tightly. And the bubble can prevent crack propagation and improve the mechanical properties of the composite. The bending strength and tensile strength of composite were 37.36 MPa and 25.32 MPa, which increased by 28.35 % and 23.27 %, respectively. Therefore, the composite prepared by using agricultural-forestry wastes and poly(lactic acid) possess acceptable mechanical properties, thermal stability and water resistance, expanding the scope of application.

Development of an Innovative Glass/Stainless Steel/Polyamide Commingled Yarn for Fiber–Metal Hybrid Composites

Fiber-metal hybrid composites are widely used in high-tech industries due to their unique combination of mechanical, toughness and ductile properties. Currently, hybrid materials made of metals and high-performance fibers have been limited to layer-by-layer hybridization (fiber-metal laminates). However, layer-by-layer hybridization lacks in fiber to fiber mixing, resulting in poor inter-laminar interfaces. The objective of this paper was to establish the fundamental knowledge and application-related technological principles for the development and fabrication of air-textured commingled yarn composed of glass (GF), stainless steel (SS) and polyamide-6 (PA-6) filaments for fiber-metal hybrid composites. For this purpose, extensive conceptual, design and technological developments were carried out to develop a novel air-texturing nozzle that can produce an innovative metallic commingled yarn. The results show that an innovative metallic commingled yarn was developed using fiber-metal hybrid composites with a composite tensile strength of 700 ± 39 MPa and an E-modulus of 55 ± 7. This shows that the developed metallic commingled yarn is a suitable candidate for producing metal-fiber hybrid composites.

Effect of Alkalized Pineapple Leaf Fiber Direction Variations on Tensile Strength and Bending of Polyester Matrix Composites

Pineapple plant is a plant that is often found throughout Indonesia, so that the production of pineapple is very abundant. Pineapple leaf fiber which consists of about 70-80% cellulose provides high modulus and strength properties, this causes pineapple leaves to be used as an efficient reinforcement of natural fiber composites. In this study, the material used was pineapple leaf fiber which had been alkalized in the direction of 0°, 45°, 90° with a volume fraction of 50% with alkalization (NaOH) treatment for 1 hour and 2 hours, without treatment. This study used polyester resin as the matrix with the hand lay up method. The test results for the pineapple leaf fiber composites which have been alkalized with variations in direction 0°, 45°, 90° with a volume fraction of 50%. And the highest value in the tensile test with treatment is in the 0° direction with a value of 5.883 MPa and an average value of 4.306 MPa with 2 hours of immersion and for the bending test the highest value is in the 0° direction with a value of 3.922 MPa and an average value of 3.276 MPa with 2 hours immersion. The 0° fiber direction has the best stress because the fiber direction is directly proportional to the static load given to the tensile and bending testing machine. Conversely, the direction of 90° is inversely proportional because the direction is not the same as the static load that is given

Mechanical and Thermal Properties of Wood-Fiber-Based All-Cellulose Composites and Cellulose-Polypropylene Biocomposites.

This article explores wood-fiber-based fabrics containing Lyocell yarn in the warp and Spinnova-Lyocell (60%/40%) yarn in the weft, which are used to form unidirectional all-cellulose composites (ACC) through partial dilution in a NaOH-urea solution. The aim is to investigate the role of the yarn orientation in composites, which was conducted by measuring the tensile properties in both the 0° and 90° directions. As a reference, thermoplastic biocomposites were prepared from the same fabrics, with biobased polypropylene (PP) as the matrix. We also compared the mechanical and thermal properties of the ACC and PP biocomposites. The following experiments were carried out: tensile test, TGA, DSC, DMA, water absorption test and SEM. The study found no significant difference in tensile strength regarding the Spinnova-Lyocell orientation between ACC and PP biocomposites, while the composite tensile strength was clearly higher in the warp (Lyocell) direction for both composite variants. Elongation at break doubled in ACC in the Lyocell direction compared with the other samples. Thermal analysis showed that mass reduction started at a lower temperature for ACC, but the thermal stability was higher compared with the PP biocomposites. Maximum thermal degradation temperature was measured as being 352 °C for ACC and 466 °C for neat PP, and the PP biocomposites had two peaks in the same temperature range (340-474 °C) as ACC and neat PP combined. ACCs absorbed 93% of their own dry weight in water in just one hour, whereas the PP biocomposites BC2 and BC4 absorbed only 10% and 6%, respectively. The study highlights the different properties of ACC and PP reference biocomposites that could lead to further development and research of commercial applications for ACC.

Evaluation of Light Cementitious Matrix with Composite Textile Reinforcement from Garment Waste.

The use of recycled waste has been the focus of several studies due to its potential to allow a more sustainable use of construction materials and minimize improper waste disposal in landfills or incinerators. More specifically, garment textile waste has been examined as internal reinforcement of cementitious matrices to increase the deformability and control fissure formation. In this study, polyester textiles are analyzed and incorporated in cementitious composites in order to evaluate their mechanical properties. Results show that significant improvements in mechanical properties of composites are obtained depending on the impregnation treatment applied to the textile waste. In the direct tensile stress test, the waste impregnation with styrene butadiene polymer plus silica fume improved 35.95% in the weft direction and 9.33% in the warp direction. Maximum stress increased 53.57% and 64.48% for composites with styrene-butadiene rubber impregnation and styrene-butadiene rubber plus silica fume impregnation, respectively, when compared to the unreinforced composite. The flexural tensile strength of composites impregnated reinforcements with styrene-butadiene rubber and styrene-butadiene rubber plus silica fume presented increases in strength by 92.10% and 94.73%, respectively, when compared to the unreinforced sample. The impact test confirmed that styrene-butadiene rubber plus silica fume impregnation produced greater tenacity of the composite. In the microstructure, it is confirmed that the impregnated textile reinforcement resulted in composites with greater adhesion between the fabric and the cementitious matrix. Thus, light textile waste is concluded to be a viable construction material for non-structural elements.

Evaluation of Thermal Adsorption and Mechanical Behaviour of Intralaminar Jute/Sisal/E-Glass Fibre-Bonded Epoxy Hybrid Composite as an Insulator

A thermal gravimetric analyzer analyzed the thermal adsorption properties of developed composites with the temperature range of 28°C–650°C at a 20°C/min constant heat flow rate. The epoxy hybrid composites were synthesized using natural jute/sisal fibre hybridized with the addition of synthetic E-glass fibres at 0-degree, 0/90-degree, and intralaminar orientations through the wet filament-winding process. The effects of orientations on tensile, flexural, and impact strengths of epoxy hybrid composites were studied using ASTM D3039, D790, and D6110. The evaluated results were compared, and the epoxy hybrid composite containing intralaminar orientations found better thermal stability with reduced weight loss at 650°C. Similarly, the test result for mechanical studies of the hybrid composite showed superior tensile, flexural, and impact strengths. The epoxy hybrid composite with intralaminar orientation was found to have a maximum tensile, impact, and flexural strength of 61.91 MPa, 770.61 J/m, and 83.90 MPa, respectively.

Development and Evaluation of Recycled Polypropylene and Bean Pod Powder Composite Biomaterial for Fused Filament Fabrication

Approximately 450 million tons of plastic and agricultural waste are produced each year in the world. Only a small portion of this plastic waste is recycled, and a small portion of this agricultural waste is used as fuel or fertilizer, and the rest of this waste is left in the environment or is burned, resulting in environmental and air pollution. For proper disposal, plastic and agricultural waste can be used in the manufacture of composites as raw materials. In this study, we had evaluated the use of bean pod powder (BPp) was used as natural reinforcing filler in recycled polypropylene (rPP) based composites. BPp/rPP composite filaments were developed using the extrusion method and the samples were printed by Fused Filament Fabrication (FFF). Composites with rPP matrix containing different weight fractions of BPp (5%, 10% and 15%) were fabricated to observe and compare the mechanical properties (tensile, flexural, and compressive strength) of the filament composites. In addition, the filament surface was analyzed for roughness and particle size of bean pod powder. The results established that BPp/rPP composites exhibited better tensile, flexural, and compressive strength than rPP and pure PP. By adding 5 wt% BPp, the tensile strength of rPP increased from 20.4 MPa to 22.8 MPa. The highest flexural strength (15.05 MPa) was obtained at 5 wt% BPp among all composites and the highest compressive strength (24.5 MPa), was obtained at 10 wt% BPp. Therefore, it can be concluded that by carefully selecting the ratio of BPp to bean pod powder, it is therefore possible to positively influence the mechanical properties of the resulting composite.

PERFORMANCE EVALUATION OF HONEYCOMB FOAM CORE HYBRID SANDWICH COMPOSITES WITH VARYING FIBER REINFORCED POLYMER SKIN

This research is an analysis of a unique high-density honeycomb foam named Lantor Soric, a flexible core material specifically used for resin infusion. To understand the full scope of this unique core material, it was bonded with various synthetic, natural, and hybrid face sheets. The glass, carbon, and jute fibers were utilized to prepare the face sheets, and epoxy was used as a binder. The sandwich composite samples were developed by a vacuum resin infusion technique. The performance of the sandwich composite, such as water absorption, flammability, and tensile and flexural strength, revealed that the addition of honeycomb foam to the composite structure improved the performance, such as water absorption, flammability, and tensile and flexural strength of the sandwich composite. The honeycomb foam was able to distribute the resin evenly throughout the laminate via its flow channels. Also, the hybrid composite of natural and synthetic fibers showed some astonishing properties in mechanical testing. The failure mechanism of the sandwich composite was inspected using scanning electron microscopy. Fractography revealed that the main mechanism for the failure was fiber pull out, voids, and interfacial debonding.

Analysis of Mechanical Properties of Kenaf and Kapok Fiber Reinforced Hybrid Polyester Composite

ABSTRACT Natural fiber reinforced hybrid polymer composites have attracted many researchers’ attention compared to synthetic fiber composites due to their better mechanical properties. Besides being inexpensive, natural fibers are eco-friendly. In the literature, kenaf fiber has shown an enormous future for its suitability in technical applications. The present studies explore the mechanical properties of kenaf and kapok fiber reinforced hybrid polyester composites. The composites are prepared by simple hand lay-up technique. The test specimens were prepared according to ASTM standards and the tensile, bending, and impact strength was evaluated experimentally. The result shows that composite with equal contribution of kenaf and kapok fiber reinforcement has tensile and impact strength of 25.25 ± 4.29 MPa and 46.65 ± 0.01 KJ/m2 respectively. As the kapok fiber content increases the bending strength and bending modulus of composites decrease. The results show that the tensile and impact strength of hybrid composites has improved considerably compared to neat kapok composites. Scanning electron microscopy (SEM) was carried out to examine the fractured surfaces of tested specimens.

Pengaruh model anyaman serat kulit pohon waru (Hibiscus Tiliceus) terhadap kekuatan tarik komposit

Waru tree bark fiber (hibiscus tiliceus) has potential as a natural fiber composite reinforcement, but further research is needed by focusing on the woven fiber model on the strength of the waru tree bark composite material. The problem to be studied is "The Effect of the Model of Waru (hibiscus tiliceus) Bark Fiber Weaving on the Tensile Strength of Composites". The specific objective of this study was to analyze the effect of the woven model of hibiscus tree bark (hibiscus tiliceus) on the tensile strength of the composite in terms of ultimate strength, strain, and modulus of elasticity. The urgency of this research is that the composite of hibiscus bark fiber without woven has a tensile load concentration that is very difficult to predict, so it is necessary to have a model of woven hibiscus bark fiber. The method used in this study is an experimental method. The composite molding process uses the vaccum infusion resin method with a variety of woven models, including: Plain 1-1, Twill 2-1, Satin 3-1, Basket 2-2. The matrix used is Bisphenol A LP-1Q resin and the reinforcement used is hibiscus tiliaceus bark fiber. The analysis carried out in this study, among others: Analysis of composite tensile strength and composite fracture analysis. The type of woven fiber affects the tensile strength of the composite. Therefore, it can be recommended that waru tree bark fiber is more suitable when using basket woven model fiber (2-2) than using unidirectional fiber model.

An efficient micromechanics-based finite element model for failure analysis of laminated composites

Accurately predicting ultimate strength of composite laminate is still a great challenge, especially only based on the constituent properties. In this paper, the micromechanics Bridging Model and systematic failure criteria for the constituent materials with emphasis on matrix failures subjected to three dimensional (3D) loads are compiled into a UMAT subroutine for ABAQUS to analyze failures of a laminated composite structure. The main purpose of this research is to greatly reduce calculation costs for loading conditions of in-plane tension or compression by introducing a simplified 3D finite element model based on the Pipes-Pagano theory. In all calculation cases, only the constituent properties together with the transverse tensile strength of unidirectional composite are needed as input data. Later in this paper, sufficient illustrations of 81 different composite laminates composed of 14 material systems are analyzed to confirm the practicability of this model.

Investigation of the effects of nanoparticle reinforcement on the mechanical properties of woven composites

AbstractNanoparticles are used in many areas related to composite materials. Recently, the importance of nanoparticle‐reinforced materials in advanced technology has been gradually increasing. In this study, epoxy reinforced with various nanoparticles, and neat epoxy were used to produce woven composites. The fatigue behaviors of woven composites reinforced with various nanoparticles under tension‐compression fatigue loads were investigated. The tensile and fatigue strengths of woven composites enhanced with nanoparticles were compared with woven composites without nanoparticles. Tensile tests showed that the woven composites reinforced with nanoparticles were damaged at high loads. Fatigue tests revealed that the woven composites reinforced with nanoparticles exhibited high cycle numbers. Adding 0.5%, 1%, and %3 nano‐CuO to epoxy increased the cycle numbers of the woven composites by 25%, 67%, and 75% respectively at 60% load level. The failure mechanisms of woven type composite materials were investigated by scanning electron microscopy (SEM). Fiber fractures and delamination damages of samples were observed.

Development of the Optimal Shape and Reinforcement Structure of the Specimen for Adequate Determination of the Tensile Strength of Unidirectional Composites

Development of the Optimal Shape and Reinforcement Structure of the Specimen for Adequate Determination of the Tensile Strength of Unidirectional Composites

Micromechanics Modeling of Transverse Tensile Strength for Unidirectional CFRP Composite

Transverse tensile strength of unidirectional (UD) composites plays a key role in overall failure of fiber-reinforced composites. To predict this strength by micromechanics, calculation of actual stress in constituent matrix is essentially required. However, traditional micromechanics models can only give the volume-averaged homogenized stress rather than an actual one for a matrix, which in practice will cause large errors. In this paper, considering the effect of stress concentration on a matrix, a novel micromechanics method was proposed to give an accurate calculation of the actual stress in the matrix for UD composite under transverse tension. A stress concentration factor for a matrix in transverse tensile direction is defined, using line-averaged pointwise stress (obtained from concentric cylinder assemblage model) divided by the homogenized quantity (obtained from a bridging model). The actual stress in matrix is then determined using applied external stress multiplied by the factor. Experimental validation on six UD carbon fiber-reinforced polymer (CFRP) specimens indicates that the predicted transverse tensile strength by the proposed method presents a minor deviation with an averaged relative error of 5.45% and thus is reasonable, contrary to the traditional method with an averaged relative error of 207.27%. Furthermore, the morphology of fracture section of the specimens was studied by scanning electron microscopy (SEM). It was observed that different scaled cracks appeared within the matrix, indicating that failure of a UD composite under transverse tension is mainly governed by matrix failure. Based on the proposed approach, the transverse tensile strength of a UD composite can be accurately predicted.

Towards high-performance textile-structure composite: Unidirectional hemp fiber tape and their composite

Textile technology offers a plethora of design and production alternatives for composite reinforcements. In this study, highly aligned continuous hemp tape was produced based on hemp sliver and used to prepare unidirectional composites with optimized mechanical properties. The fiber content, preform areal density, and fiber orientation were considered to investigate the mechanical properties of the composite. The areal density of the hemp tape felt was contingent on the hemp sliver drafting multiple. Both composite tensile and flexural strength reached the maximum of 166.85 MPa and 207.68 MPa at drafting multiple i=2 and 30% fiber content, which were comparable with those reported for hemp fiber composites. The hemp tape was favorable for more complex shapes for applications. The superior mechanical properties and discrimination between the composites enhanced with two typical orthogonal reinforcement diversified the application potential in the field of automotive, furniture and architectural panels. • Hemp tape with highly aligned fibers was produced by self-designed equipment. • Low tape areal density aids fiber alignment accompanied with delamination risk. • Hemp tape-based composite properties are not proportional to fiber orientation.

Mechanical properties, thermal stability, and thermal degradation kinetics of silicone rubber/ethylene‐vinyl acetate copolymer/magnesium sulfate whisker composites compatibilized by ethylene‐acrylic acid copolymer

AbstractSilicone rubber/ethylene‐vinyl acetate copolymer/magnesium sulfate whisker composites containing ethylene‐acrylic acid copolymer (MS/SR/EVM/EAA) as a compatibilizer were successfully prepared. Moreover, the magnesium sulfate whisker surface was modified with 3 wt% of silane coupling agent (KH570), resulting in composites including (unmodified magnesium sulfate whisker) uMS/SR/EVM, (modified magnesium sulfate whisker) mMS/SR/EVM, and mMS/SR/EVM/EAA were compared. The values of thermal decomposition activation energy (Ea) calculated by the two different methods (Kissinger and Friedman methods) show that the composites filled with 5 and 20 phr whiskers have lower values of activation energy (Ea) than the SR/EVM blend. The tensile strength of composites with a 5 phr modified whisker is 14.5 MPa, which is higher than that of the SR/EVM blend and uMS5/SR/EVM composite. The tear strength of the composite with 20 phr mMS is 51.6 kN m−1, much higher than that of the composite with 20 phr uMS and SR/EVM blend. The mechanical properties were also investigated after thermal aging of the composites at 85°C for 48 h. The thermal conductivity of the composites with high filler loading was studied.

The influence of addition of carbon nanotube and graphene platelets on characteristics of carbon/basalt fiber reinforced intra‐ply hybrid composites

AbstractIn this study, effects of addition of carbon nanotubes (CNTs) and graphene platelets (GPLs) on characteristics of carbon/basalt fiber reinforced intra‐ply hybrid composites were investigated. The composites were fabricated using vacuum assisted resin infusion molding (VARIM) method in two types including bare and 0.1, 0.5 wt.% of GPL and CNT nanoparticles filled hybrid composites. Fabricated normal and multiscale composites were cut by water jet and mechanical properties of specimens were examined by tensile, flexural, SBS experiments. Therefore, the modulus of elasticity, flexural modulus, tensile and flexural strength and ILSS of bare and multiscale composites were compared. Thermomechanical properties of fabricated composites were evaluated by dynamic mechanic analyze (DMA), thermogravimetric analyze (TGA) and thermal conductivity (TC) tests and storage modulus, loss modulus, damping ratio, glass transition temperature, weight loss and derivative weight loss were compared in fabricated normal and multiscale composites. Similarly, modal properties of fabricated composites such as natural frequency and damping factor were obtained by vibrational tests and compared in fabricated composites. According to the results, the addition of carbon‐based nanoparticles improved the characteristics of carbon/basalt fiber intra‐ply hybrid composites. The response of composites was directly proportional to the addition ratio of the carbon‐based nanoparticles.

Biological oyster shell waste enhances polyphenylene sulfide composites and endows them with antibacterial properties

To date, there is no research that deals with biological waste as fillers in polyphenylene sulfide (PPS). In this study, oyster shells were recycled and treated to prepare thermally-treated oyster shells (TOS), which were used as PPS fillers to make new bio-based antibacterial composite materials. The effect of varying the content of TOS was studied by means of structure and performance characterization. PPS/TOS composites were demonstrated to have an antibacterial effect on the growth of E coli and S. aureus. Qualitative analysis showed that when the TOS content was ≥ 30% and 40%, the composite materials had an apparent inhibition zone. Quantitative analysis showed that the antibacterial activity increased with the TOS content. Fourier transform infrared spectroscopy indicated the formation of hydrogen bonds between the molecular chains of TOS and PPS and the occurrence of a coordination reaction. At 10% TOS, the composite tensile strength reached a maximum value of 72.5 MPa, which is 9.65% higher than that of pure PPS. The trend of bending properties is the same as that of tensile properties, showing that the maximum property was reached for the composite with 10% TOS. At the same time, the crystallinity and contact angle were the highest, and the permeability coefficient was the lowest. The fatigue test results indicated that for the composite with 10% TOS, the tensile strength was 23% lower than static tensile strength, and the yield strength was 10% lower than the static yield strength. The results of the study showed that TOS not only could reduce the cost of PPS, but also could impart antibacterial properties and enhance the mechanical and, barrier properties, the thermostability, as well as the crystallinity.

Water absorption behaviour of glass fibre-reinforced polymer composite with clamshell and cenosphere fillers

This article deals with the effect of filler material on the water absorption behaviour of glass fibre-reinforced polymer (GFRP) composites. The fillers are cenosphere and clamshell which are industrial waste and marine waste, respectively. The composite with six layers of fibre is prepared using the most common way of hand lay-up process. Different contents of filler, that is, 0, 10 and 20 wt.% of clamshell and cenosphere are added in the glass fibre-epoxy polymer. These are the wastes that have the potential to be an important filler in polymer matrix composite (PMC). The water absorption behaviour of the glass composites is studied and found that filler content plays a significant role in the water absorption property. The addition of both fillers improves the water resistance of the composites. The diffusion mechanism of water absorption of the present composites follows the non-Fickian type. Composites with cenosphere filler show better water resistance when compared to composites with clamshell filler. The effect of moisture absorption on the tensile strength of composites is also investigated which shows that the tensile strength of the composites is degraded after water immersion. The degradation of the tensile strength in the composite is lower in the case of saline water when compared to distilled water. Tensile strength of the composite is increased with the addition of filler and is highest in glass fibre-epoxy composite at 20 wt.% for both clamshell and cenosphere fillers. 20 wt.% of clamshell filler in the composite shows better tensile strength when compared to 20 wt.% of cenosphere in the composite.

Effect of fibre stacking orientation on the mechanical and thermal properties of laminated kenaf fibre/epoxy composites

ABSTRACT Natural fibre-reinforced composites have been developed by researchers and industries as a solution to reduce the use of synthetic fibres. Kenaf fibre is one of the most abundant natural fibres in Indonesia. This study aimed to obtain the mechanical and thermal properties of kenaf fibre-reinforced epoxy laminated composites fabricated using a vacuum-assisted resin infusion method. The alkaline-treated fibres were arranged in the orientations 0°/0°/0°/0° and 0°/90°/0°/90°. Density measurements, mechanical tests, and thermogravimetric analysis were carried out on the epoxy and the composites. The results of the mechanical testing showed that the tensile, flexural, and compression strengths of the kenaf fibre-reinforced epoxy composites with a 0°/0°/0°/0° fibre orientation were higher than those of the composites with a 0°/90°/0°/90° fibre orientation, with values of (96.61 ± 10.18) MPa, (131.01 ± 6.60) MPa, and (71.96 ± 5.50) MPa, respectively. Scanning electron microscope observations showed that the composites had good fibre-matrix adhesion. The thermal stability of the epoxy was enhanced from 557 °C to 571 °C by incorporating kenaf fibre with 0°/0°/0°/0° orientation. With reference to the Indonesian National Standard 01-4449–2006, the two composites could be classified as T2 45 High Density Fibreboard.