scholarly journals Fabrication and Mechanical Performance of Non-Crimp Unidirectional Jute-Yarn Preform-Based Composites

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6664
Author(s):  
Yeasin Ali ◽  
Atik Faisal ◽  
Abu Saifullah ◽  
Hom N. Dhakal ◽  
Shah Alimuzzaman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Woven Composites ◽  
Weft Yarn ◽  
Warp Yarn ◽  
Load Bearing ◽  
Load Carrying ◽  
Jute Yarn

This work developed novel jute-yarn, non-crimp, unidirectional (UD) preforms and their composites, with three different types of warp jute yarns of varying linear densities and twists in the dry UD preforms, in order to present a possible solution to the detrimental effects of higher yarn twists and crimp at the warp–weft yarn interlacements of traditional, woven, preform-based composites on their mechanical properties. In the developed UD preforms, warp jute yarns were placed in parallel by using a wooden picture-frame pin board, with the minimal number of glass weft yarns to avoid crimp at the warp–weft yarns interlacements, which can significantly enhance the load-bearing ability of UD composites compared to traditional, woven, preform composites. It was found that an optimal combination of jute warp yarn linear densities and twists in the UD preforms is important to achieve the best possible mechanical properties of newly developed UD composites, because it encourages a proper polymer-matrix impregnation on jute fibres, leading to excellent fibre–matrix interface bonding. Composites made from the 25 lb/spindle jute warp yarn linear density (UD25) exhibited higher tensile and flexural properties than other UD composites (UD20, UD30). All the UD composites showed a much better performance compared to the traditional woven preform composites (W20), which were obviously related to the higher crimp and yarn interlacements, less load-carrying capacity, and poor fiber–matrix interfaces of W20 composites. UD25 composites exhibited a significant enhancement in tensile modulus by ~232% and strength by ~146%; flexural modulus by 138.5% and strength by 145% compared to W20 composites. This reveals that newly developed, non-crimp, UD preform composites can effectively replace the traditional woven composites in lightweight, load-bearing, complex-shaped composite applications, and hence, this warrants further investigations of the developed composites, especially on long-term and dynamic-loading mechanical characterizations.

Experimental and Modeling Study on Tension Characteristics of a 2.5D Woven Composites

2019 ◽  
Author(s):  
Xuefeng Teng ◽  
Duoqi Shi ◽  
Xiaoguang Yang
Keyword(s):  
Mechanical Properties ◽  
Image Correlation ◽  
Woven Composites ◽  
Fiber Axis ◽  
Weft Yarn ◽  
Fe Model ◽  
Load Bearing ◽  
Full Field ◽  
Deformation Features ◽  
Local Fiber

Abstract 2.5D woven composites have recently attracted much attention in the fields of aerospace and automobile industry due to their excellent properties such as low density, high thermal shock resistance, high specific strength and enhanced mechanical properties. Before the 2.5D woven composites are applied as load-bearing structure, it is necessary to have an in-depth understanding of their mechanical behavior and load transfer mechanism under external loads. In this paper, in-plane tensile tests including longitude direction and transverse direction were conducted for a 2.5D woven SiO2f/SiO2 composites at room temperature. With the full-field displacements and strains retrieved by digital image correlation (DIC) method, the mechanical properties and deformation features of the 2.5D woven composites were obtained and observed. The results show that the composite has a lower elastic modulus and fracture strength in the weft direction, and the warp yarn has weaker mechanical properties than weft yarn in the loading direction due to its crimp feature. Remarkable deformation features of the full-field displacement and strain distributions were observed, indicating that the woven structure has a great influence on the deformation evolution and load-bearing mechanism of the composite. Also, based on the actual geometrical architecture of the composite, a mesoscale finite element (FE) model was established and the deformation characteristics of the material were analyzed. The crimp of the warp yarns causes the local fiber axis to rotate with respect to the global coordinate system, which causes the effective modulus in the global direction to vary. Local coordinate systems were assigned to each node such that the local 1 direction is always parallel to the local fiber axis along the length of the warp yarns, which improves the accuracy of the simulation results. Deformation features of the 2.5D woven SiO2f/SiO2 composites were obtained in FEM simulation and discussed comparing with experimental results.

Study of the annealing influence on the mechanical performance of PA12 and PA12 fibre reinforced FFF printed specimens

2020 ◽  
Vol 26 (10) ◽  
pp. 1761-1770
Author(s):  
Isaac Ferreira ◽  
Carolina Melo ◽  
Rui Neto ◽  
Margarida Machado ◽  
Jorge Lino Alves ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Annealing Treatment ◽  
Degree Of Crystallinity ◽  
Fibre Reinforcement ◽  
Scanning Calorimetry ◽  
Content Type ◽  
The Degree Of Crystallinity

Purpose The purpose of this study is to evaluate and compare the mechanical performance of FFF parts when subjected to post processing thermal treatment. Therefore, a study of the annealing treatment influence on the mechanical properties was performed. For this, two different types of Nylon (PA12) were used, FX256 and CF15, being the second a short fibre reinforcement version of the first one. Design/methodology/approach In this study, tensile and flexural properties of specimens produced via FFF were determined after being annealed at temperatures of 135°C, 150°C or 165°C during 3, 6, 12 or 18 h and compared with the non-treated conditions. Differential scanning calorimetry (DSC) was performed to determine the degree of crystallinity. To evaluate the annealing parameters’ influence on the mechanical properties, a full factorial design of experiments was developed, followed by an analysis of variance, as well as post hoc comparisons, to determine the most significative intervening factors and their effect on the results. Findings The results indicate that CF15 increased its tensile modulus, strength, flexural modulus and flexural strength around 11%, while FX256 presented similar values for tensile properties, doubling for flexural results. Flexural strain presented an improvement, indicating an increased interlayer behaviour. Concerning to the DSC analysis, an increase in the degree of crystallinity for all the annealed parts. Originality/value Overall, the annealing treatment process cause a significant improvement in the mechanical performance of the material, with the exception of 165°C annealed specimens, in which a decrease of the mechanical properties was observed, resultant of material degradation.

scholarly journals EFFECT OF HUMIDITY ON THE MECHANICAL PROPERTIES OF KENAF YARN FIBRE/POLYLACTIC ACID BIOCOMPOSITES

2019 ◽  
Vol 81 (5) ◽  
Author(s):  
Meor Syazalee ◽  
Rozli Zulkifli
Keyword(s):  
Mechanical Properties ◽  
Relative Humidity ◽  
Polylactic Acid ◽  
Mechanical Performance ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Mechanical Analysis ◽  
Natural Fibre ◽  
Static Mechanical ◽  
And Storage

Humidity during the fabrication of natural fibre reinforced composites can harm their mechanical performance. This study examines the effect of humidity during the fabrication of unidirectional kenaf/polylactic acid (PLA) biocomposites on their dynamic and static mechanical properties. Kenaf fibres were conditioned at different relative humidity (RH) levels (40% RH, 60% RH and 80% RH) before being pressed with PLA to form biocomposites. Kenaf/PLA biocomposites were analysed using dynamic mechanical analysis, fracture toughness in mode II, tensile and flexural. Results indicated that the value of GIIC and storage modulus decreased when the relative humidity increased. Reduced tensile and flexural modulus were observed when kenaf was exposed to high relative humidity of 80% RH. However, the form of unidirectional kenaf affected the properties and reduced the drop value in the tensile modulus. The optimum relative humidity to produce kenaf/PLA biocomposites is 40% RH.

scholarly journals Improving the mechanical properties of polypropylene composites with coconut shell particles

2021 ◽  
Vol 30 ◽  
pp. 263498332110074
Author(s):  
Henry C Obasi ◽  
Uchechi C Mark ◽  
Udochukwu Mark
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Flexural Modulus ◽  
Filler Particle ◽  
Tensile Modulus ◽  
Coconut Shell ◽  
Polypropylene Composites ◽  
Increase With Increase ◽  
Pp Composites ◽  
Shell Particles

Conventional inorganic fillers are widely used as fillers for polymer-based composites. Though, their processing difficulties and cost have demanded the quest for credible alternatives of organic origin like coconut shell fillers. Dried shells of coconut were burnt, ground, and sifted to sizes of 63, 150, 300, and 425 µm. The ground coconut shell particles (CSP) were used as a filler to prepare polypropylene (PP) composites at filler contents of 0% to 40% via injection melt blending process to produce PP composite sheets. The effect of the filler particle size on the mechanical properties was investigated. The decrease in the size of filler (CSP) was found to improve the yield strength, tensile strength, tensile modulus, flexural strength, flexural modulus, and hardness of PP by 8.5 MPa, 15.75 MPa, 1.72 GPa, 7.5 MPa, 100 MPa, and 10.5 HR for 63 µm at 40%, respectively. However, the elongation at break and modulus of resilience of the PP composites were seen to increase with increase in the filler size. Scanning electron microscope analysis showed that fillers with 63 µm particle size had the best distribution and interaction with the PP matrix resulting in enhanced properties.

A CASE STUDY OF BIOCOMPOSITE MATERIAL USE IN AUTOMOTIVE APPLICATIONS

2021 ◽  
Author(s):  
DANIEL WALCZYK ◽  
RONALD BUCINELL ◽  
STEVEN FLEISHMAN ◽  
SHARMAD JOSHI
Keyword(s):  
High Performance ◽  
Mechanical Performance ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Maximum Tensile Stress ◽  
High Viscosity ◽  
Flexural Stress ◽  
Fiber Volume ◽  
Low Viscosity ◽  
Biocomposite Material

Interest in biocomposites is growing worldwide as companies that manufacture high-performance products seek out more sustainable material options. Although there is significant research on biocomposite material options and processing found in the literature from at least the last two decades, there are few experimentally based case studies published to help guide product designers and engineers when considering these materials. This paper discusses the use of biocomposites in the seat of an electric bus. Although it is clear that biocomposite material options are quite limited, the authors eventually settled on three natural reinforcements (cellulose, hemp, flax), two epoxies (one low and the other high viscosity) with high biobased carbon content, and one flax precoated with bioepoxy for consideration. Laminate plates with a 4mm nominal thickness are manufactured using VARTM (low viscosity epoxy only), hand layup as a surrogate for prepregging (high viscosity epoxy only), compression molding, and an out-of-autoclave process called the Pressure Focusing Layer (PFL) method. Permeability of the three reinforcements infused with the high viscosity epoxy and fiber volume fractions are determined experimentally to provide insight into VARTM processing and mechanical performance. The tensile modulus, maximum tensile stress, flexural modulus, and maximum flexural stress are measured for all combinations of reinforcement, resin, and processing using tension testing and three-point bending based on ASTM standards. Basic conclusions are drawn about the specific application and more generally about the process of using biocomposites in commercial products.

scholarly journals Effect of Kenaf Alkalization Treatment on Morphological and Mechanical Properties of Epoxy/Silica/Kenaf Composite

2018 ◽  
Vol 7 (4.35) ◽  
pp. 258 ◽  
Author(s):  
Che Nor Aiza Jaafar ◽  
Muhammad Asyraf Muhammad Rizal ◽  
Ismail Zainol
Keyword(s):  
Mechanical Properties ◽  
Sodium Hydroxide ◽  
Mechanical Performance ◽  
Flexural Modulus ◽  
Charpy Impact ◽  
Charpy Impact Test ◽  
Curing Temperature ◽  
Curing Process ◽  
Scanning Calorimetry ◽  
Kenaf Fiber

The mechanical performance of silica modified epoxy at various concentration of sodium hydroxide for surface treatment of multi-axial kenaf has been analyzed. Epoxy resin with amine hardener was modified with silica powder at 20 phr and toughened by treated kenaf fiber that immerses in various concentrations of sodium hydroxide (NaOH) ranging from 0% to 9% of weight. The composite was analyzed through differential scanning calorimetry (DSC) to ensure complete curing process. The mechanical properties of the composites were analyzed through flexural test, Charpy impact test and DSC to ensure the complete curing process. DSC analysis results show epoxy sample was completely cured at above 73°C that verifies the curing temperature for preparation for the composite. Hence, 3% NaOH treated composite exhibits the best mechanical properties, with 10.6 kJ/m2 of impact strength, 54.1 MPa of flexural strength and 3.5 GPa of flexural modulus. It is due to the improvement of fiber-matrix compatibility. Analysis by SEM also revealed that a cleaner surface of kenaf fiber treated at 3% NaOH shown cleaner surface, thus, in turn, improve surface interaction between fiber and matrix of the composite. The composites produced in this work has high potential to be used in automotive and domestics appliances.

scholarly journals Effect of MWCNT on Thermal, Mechanical, and Morphological Properties of Polybutylene Terephthalate/Polycarbonate Blends

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
C. P. Rejisha ◽  
S. Soundararajan ◽  
N. Sivapatham ◽  
K. Palanivelu
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Nucleating Agent ◽  
Mechanical Analysis ◽  
Morphological Properties ◽  
Multiwall Carbon Nanotube ◽  
Polybutylene Terephthalate ◽  
The Impact

This paper evaluated the effect of multiwall carbon nanotube (MWCNT) on the properties of PBT/PC blends. The nanocomposites were obtained by melt blending MWCNT in the weight percentages 0.15, 0.3, and 0.45 wt% with PBT/PC blends in a high performance corotating twin screw extruder. Samples were characterized by tensile testing, dynamic mechanical analysis, thermal analysis, scanning electron microscopy, and X-ray diffraction. Concentrations of PBT and PC are optimized as 80 : 20 based on mechanical properties. A small amount of MWCNT shows better increase in the thermal and mechanical properties of the blends of PBT/PC nanocomposite when compared to nanoclays or inorganic fillers. The ultimate tensile strength of the nanocomposites increased from 54 MPa to 85 MPa with addition of MWCNT up to 0.3% and then decreased.The tensile modulus values were increased to about 60% and the flexural modulus was more than about 80%. The impact strength was also improved with 20% PC to about 60% and with 0.15% MWCNT to about 50%. The HDT also improved from 127°C to 205°C. It can be seen from XRD result that the crystallinity of PBT is less affected by incorporating MWCNT. The crystallizing temperature was increased and the MWCNT may act as a strong nucleating agent.

Finite element analysis of a personalized femoral scaffold with designed microarchitecture

2009 ◽  
Vol 224 (7) ◽  
pp. 877-889 ◽  
Author(s):  
P Pandithevan ◽  
G Saravana Kumar
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Computer Aided Design ◽  
Strain State ◽  
Mechanical Performance ◽  
Physiological Stress ◽  
Tissue Growth ◽  
Bone Tissue Regeneration ◽  
Load Bearing ◽  
Ct Data

Tissue engineering scaffolds with intricate and controlled internal structure can be realized using computer-aided design (CAD) and layer manufacturing (LM) techniques. Design and manufacturing of scaffolds for load-bearing bone sites should consider appropriate biocompatibile materials with interconnected porosity, surface properties, and sufficient mechanical properties that match the surrounding bone, in order to provide adequate support, and to mimic the physiological stress—strain state so as to stimulate new tissue growth. The authors have previously published methods for estimating subject- and site-specific bone modulus using computed tomography (CT) data, CAD, and process planning for LM of controlled porous scaffolds. This study evaluates the mechanical performance of the designed porous hydroxyapite scaffolds in load-bearing sites using a finite element (FE) approach. A subject-specific FE analysis using femoral, defect site geometry and anisotropic material assignment based on CT data is employed. Mechanical behaviour of the femur with scaffold in stance-phase gait loading, which has been shown experimentally to produce clinically relevant results, is analysed. The comparison of results with simulation of healthy femur shows an overall correspondence in stress and strain state which will provide optimized mechanical properties for avoiding stress shielding, and adequate strength to avoid failure risk and for active bone tissue regeneration.

scholarly journals Investigation of Cure Reaction, Rheology, Volume Shrinkage and Thermomechanical Properties of Nano-TiO2 Filled Epoxy/DDS Composites

2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
Jyotishkumar Parameswaranpillai ◽  
Abhilash George ◽  
Jürgen Pionteck ◽  
Sabu Thomas
Keyword(s):  
Mechanical Properties ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Thermomechanical Properties ◽  
Diglycidyl Ether ◽  
Volume Shrinkage ◽  
Heat Of Reaction ◽  
Nano Tio2 ◽  
Cure Reaction ◽  
Good Improvement

The cure reaction, rheology, volume shrinkage, and thermomechanical behavior of epoxy-TiO2 nanocomposites based on diglycidyl ether of bisphenol A cured with 4,4′-diaminodiphenylsulfone have been investigated. The FTIR results show that, at the initial curing stage, TiO2 acts as a catalyst and facilitates the curing. The catalytic effect of TiO2 was further confirmed by the decrease in maximum exothermal peak temperature (DSC results); however, it was also found that the addition of TiO2 decreases the overall degree of cure, as evidenced by lower total heat of reaction of the cured composites compared to neat epoxy. The importance of cure rheology in the microstructure formation during curing was explored by using rheometry. From the PVT studies, it was found that TiO2 decreases the volume shrinkage behavior of the epoxy matrix. The mechanical properties of the cured epoxy composites, such as tensile strength, tensile modulus, flexural strength, flexural modulus, impact strength, and fracture toughness of the polymer composites, were examined. The nanocomposites exhibited good improvement in dimensional, thermal, and mechanical properties with respect to neat cross-linked epoxy system. FESEM micrographs of fractured surfaces were examined to understand the toughening mechanism.

Effects of the Size of Wood Flour on Mechanical Properties of Wood-Plastic Composites

2011 ◽  
Vol 393-395 ◽  
pp. 76-79 ◽  
Author(s):  
Hai Bing Huang ◽  
Hu Hu Du ◽  
Wei Hong Wang ◽  
Hai Gang Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Wood Flour ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Inorganic Filler ◽  
Full Potential ◽  
Wood Plastic Composites ◽  
Plastic Composites

In this article, wood-plastic composites(WPCs) were manufactured with wood flour(80～120mesh、40～80mesh、20～40mesh、10～20mesh) combing with high density polyethylene(HDPE). Effects of the size of wood flour on mechanical properies and density of composites were investigated. Results showed that particle size of wood flour had an important effect on properitiesof WPCs. Change of mesh number had a outstanding effect on flexural modulus, tensile modulus and impact strength, howere, little effect on flexural strength and tensile strength. When mesh number of wood flour changed from 80～120mesh to 10～20mesh,flexural modulus and tensile modulus were respectively enhanced by 42.4% and 28.4%, respectively, and impact strength was decreased by 35.5%.Size of wood flour basically had no effect on density of composite within 10～120mesh. The use of wood flour or fiber as fillers and reinforcements in thermoplastics has been gaining acceptance in commodity plastics applications in the past few years. WPCs are currently experiencing a dramatic increase in use. Most of them are used to produce window/door profiles,decking,railing,ang siding. Wood thermoplastic composites are manufactured by dispering wood fiber or wood flour(WF) into molten plastics to form composite materials by processing techniques such as extrusion,themoforming, and compression or injection molding[1]. WPCs have such advantages[2]：(1)With wood as filler can improve heat resistance and strength of plastic, and wood has a low cost, comparing with inorganic filler, wood has a low density. Wood as strengthen material has a great potential in improving tensile strength and flexural modulus[3]；(2) For composite of same volume, composites with wood as filler have a little abrasion for equipment and can be regenerated；(3)They have a low water absorption and low hygroscopic property, They are not in need of protective waterproof paint, at the same time, composite can be dyed and painted for them own needs；(4)They are superior to wood in resistantnce to crack、leaf mold and termite aspects, composites are the same biodegradation as wood；(5)They can be processed or connected like wood；（6）They can be processed into a lots of complicated shape product by means of extrusion or molding and so on, meanwhile, they have high-efficiency raw material conversion and itself recycle utilization[4]. While there are many sucesses to report in WPCs, there are still some issues that need to be addressed before this technology will reach its full potential. This technology involves two different types of materials: one hygroscopic(biomass) and one hydrophobic(plastic), so there are issues of phase separation and compatibilization[5]. In this paper, Effects of the size of wood powder on mechanical properties of WPCs were studied.

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