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0000-0003-3847-5469
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Publisher: Elsevier BV
Date: 05-2013
Publisher: Elsevier BV
Date: 08-2008
Publisher: Elsevier BV
Date: 07-2014
Publisher: World Scientific Pub Co Pte Lt
Date: 20-09-2010
DOI: 10.1142/S0217979210056633
Abstract: The effect of two types of oil palm fibres (bunch and fruit) on mechanical properties of polyester composites is examined in the current work considering different volume fractions. Tensile, compression, and flexural properties of the composites were investigated. In addition to that, tensile strengths were calculated theoretically using Hirsch model. Scanning electron microscope (SEM) was used to observe the fracture mechanism of the specimens. Single fibre pull-out tests were performed to determine the interfacial shear strength between polyester resin and both types of oil palm fibres. Results revealed that both types of oil palm fibres enhanced the mechanical performance of polyester composites. At a higher volume fraction (40–50%), tensile strength of the polyester composite was improved, i.e., 2.5 times improvement in the tensile strength value. Experimental tensile strength values of oil palm bunch olyester composites have a good correlation with the theoretical results, especially at low volume fractions of fibre. Flexural strength of polyester worsened with oil palm fibres at all volume fractions of fibre.
Publisher: Informa UK Limited
Date: 2012
Publisher: SAGE Publications
Date: 11-12-2008
Abstract: The current work is an attempt to use betelnut fibres as reinforcement for tribo-polyester composite. The composite was fabricated using hand lay-up technique. It consists of 13 layers of randomly distributed betelnut fibre mats and 15 layers of polyester. Wear and frictional behaviours of the composite were studied against a polished stainless steel counterface using a newly developed block-on-disc machine. Tests were conducted at 2.8 m/s sliding velocity, different applied loads (5-30 N), and sliding distances (0-6.72 km). In addition, the orientation of the fibre mats, with respect to the sliding direction of the counterface, was considered, i.e. anti-parallel (AP-O), parallel (P-O), and normal (N-O). The worn surface morphology was studied using a scanning electron microscope. Optical microscopy was used to observe the wear track surface on the counterface. In addition, the modifications on the counterface roughness were studied. This work revealed that the presence of betelnut fibre in the matrix, namely P-O, enhanced the wear and frictional performance of the polyester by about 98 and 73 per cent. Applied load has less effect on the specific wear rate and friction coefficient of the composite, especially in P-O and AP-O. The composite behaved differently in N-O in which the wear and friction increased when the applied load and sliding distance increased. The composite exhibited higher wear performance in P-O compared with AP-O followed by N-O. In N-O, poor support of the fibres to the resinous was observed, i.e delamination, pullout, and breakage in the fibres. In AP-O, the wear mechanism was predominated by plastic deformation, micro- and macro-cracks in the resinous regions associated with pullout, and breakage of the fibre. In P-O, debonding of fibres was the main wear mechanism.
Publisher: Elsevier BV
Date: 2014
Publisher: MDPI AG
Date: 23-09-2022
Abstract: In recent years, there has been an increasing demand for engineering materials that possess good mechanical and thermal properties and are cheap an d environmentally friendly. From an industrial and academic point of view, there is a need to study the heat conductivity of newly developed polymer composites and the influence of porosity on the insulation performance of polymer composites. Experimental and theoretical studies were conducted on mainly sisal/glass fibre gypsum composites with different fibre volumes (0, 20, 25, 30, and 35 wt.%). The outcomes from the theoretical model in ANSYS have shown that there is a high possibility to simulate the experimental work and high accuracy for reflecting the experimental findings. Moreover, the results show that natural fibre polymer composites with a high-volume fraction of natural fibres have higher insulation performance than synthetic polymer composites with the same volume fraction of synthetic fibres. Furthermore, the results suggest and support that the improved performance of natural fibre-based composites was due at least in part to the internal porosity of the fibres.
Publisher: World Scientific Pub Co Pte Lt
Date: 10-11-2010
DOI: 10.1142/S0217979210056232
Abstract: This paper presents an attempt to use kenaf fibres as reinforcement for tribo-polymeric composite. Kenaf fibres reinforced epoxy (KFRE) composite was fabricated using a closed mould technique associated with vacuum system. Adhesive wear and frictional behaviour of the composite and neat epoxy (NE) were studied against polished stainless steel counterface using a newly developed block-on-disc (BOD) machine at 50N applied load, sliding distances (0–4.2 km) and sliding velocities of 2.8 m/s. The morphology of the worn surfaces of the composite and NE was studied using a scanning electron microscope (SEM). The result revealed that the longer the sliding distance is, the higher the weight loss. Up to 70% reduction in the weight loss was achieved when the epoxy was reinforced with the kenaf fibres. The wear mechanism was predominated by plastic deformation, in the resinous regions and debonding of fibres.
Publisher: World Scientific Pub Co Pte Lt
Date: 08-2008
DOI: 10.1142/S0218625X08011482
Abstract: Steel wires are implemented in numerous systems and undergo frequent faults due to tribological loading conditions. Therefore, this paper presents a study on the tribological performance of steel wire sliding against different counterfaces, namely, aluminum alloy, stainless steel, and mild steel using a block-on-ring tribo-tester. According to common mechanisms, the tests were performed under 5 N applied load and 0.15 m/s sliding velocity under dry contact condition. Additionally, scanning electron microscopy was used to examine the damaged features on the worn surfaces of the steel wire. Weight loss and friction coefficient results were presented versus sliding distances (0–1.6 km). In general, the results showed that friction coefficient did not reach the steady state due to the transformation of the wear mechanism from adhesive to abrasive mode. Nevertheless, the average of friction coefficient was found to be about 0.7 ± 0.1 for stainless steel and 0.2 ± 0.1 for mild steel. Weight loss gradually increased with the increase of sliding distance. The micrographs of worn surfaces revealed that the contact mechanism was transformed from adhesive to abrasive wear mode as implied by the scars and grooves on the wire surface.
Publisher: SAGE Publications
Date: 09-2010
Abstract: The present work is an attempt to investigate the mechanical properties of a treated betelnut fibre-reinforced polyester composite. Tensile, flexural, compression, and hardness tests were carried out. As a result of reinforcing the polyester with the treated betelnut fibre mats, the tensile, flexural, compression, and hardness properties of the composite were enhanced by about 141 per cent, 28 per cent, 85 per cent, and 6 per cent when compared to neat polyester. The high roughness of the outer layer of the treated betelnut fibre and the presence of trichomes were the main reasons for the high enhancement of mechanical properties of the composites. Scanning electron microscopy observation showed low fibre pullout during the mechanical test. The failure mechanism was dominated by fibre breakage and slight debonding during the tensile tests.
Publisher: Elsevier BV
Date: 06-2013
Publisher: Wiley
Date: 23-02-2013
Publisher: Elsevier BV
Date: 04-2012
Publisher: Elsevier BV
Date: 04-2007
Publisher: Elsevier BV
Date: 08-2011
Publisher: World Scientific Pub Co Pte Lt
Date: 12-2007
DOI: 10.1142/S0218625X07010561
Abstract: In the present work, the effect of oil palm fibers on tribological performance of polyester composite against a polished stainless steel counterface is investigated using a pin-on-disc machine. Wear and friction characteristics of oil palm fiber reinforced polyester (OPRP) composite and neat polyester were tested at different sliding distances (0–5 km), sliding velocities (1.7–3.9 m/s), and applied loads (30–70 N) under dry contact condition. SEM observations were performed on the worn surfaces to examine the damage features. The results showed that the test parameters significantly influenced the tribo-performance of OPRP composite and neat polyester. The presence of oil palm fiber in the polyester enhanced the wear property by about three to four times compared to neat polyester. In addition, the friction coefficient of OPRP composite was less by about 23% than that of the neat polyester. Wear mechanisms of OPRP composite were categorized by debonding, bending and tear of fibers, and high deformation in resinous region.
Publisher: Elsevier BV
Date: 12-2010
Publisher: ASMEDC
Date: 2007
Abstract: In the present work, effects of two types of natural fibres on mechanical properties of polyester composites were investigated at different volume fractions of fibre. Tensile, compression, and flexural properties of oil palm bunch and oil palm fruit fibres reinforced polyester composites were investigated. Additionally, tensile strength of the selected composites was calculated theoretically. Scanning electron microscope was used to observe the fracture mechanism of the specimens. Single fiber pull-out tests were carried out to determine the interfacial shear strength between polyester resin and both types of oil palm fibre. As results, it was found that both types of oil palm fibre enhanced the mechanical performance of polyester composites. At higher volume fraction (≈41%), tensile strength was improved, when polyester reinforced with oil palm fruit fibres, i.e. 2.5 folds improvement in the tensile strength value. Further, experimental tensile strength values of oil palm bunch olyester composites was found to be less varied compared to theoretical results. Flexural strength of polyester was worsened with oil palm fibres at all of fibre volume fraction.
Publisher: Elsevier BV
Date: 09-2009
Publisher: ASMEDC
Date: 2009
Abstract: In the present work, wear and frictional characteristics of thermoplastic epoxy resin reinforced with treated kenaf fiber (T-KFRE) is investigated. The T-KFRE composite was tested against smooth stainless steel using a block on disc (BOD) apparatus at 2.8m/s sliding velocity and variable applied loads (10–60N) and sliding distance (02.7km). The T-KFRE was investigated under Parallel (PO) in relation to sliding direction. Adhesive wear results revealed that T-KFRE has a superior and high degree of wear resistance when slid against a stainless steel counter face in comparison to neat epoxy. The friction coefficient varied between the ranges of 0.35 and 0.65 in relative to sliding distance of up to 2.7 km. SEM study showed different wear mechanism such as pitting, delamination, breakage and micro cracks especially for lighter applied loads. Meanwhile, heavier loads showed less damage to the surface, which in turn exhibited, better wear performance and frictional characteristics.
Publisher: Hindawi Limited
Date: 16-10-2021
DOI: 10.1155/2021/3795831
Abstract: New lubricants based on vegetable oil were developed in this study. Different blends of canola oil mixed with fully synthetic two stock engine oils were developed (0, 20%, 40%, 60%, and 80% of synthetic oil). The viscosity of the prepared blends was determined at different temperatures (20°C–80°C). Tribological experiments were conducted to investigate the effect of the newly developed oil on the wear characteristics of mild steel material compared with stainless steel when subjected to adhesive wear loading. The weight loss (WL) and the specific wear rate (SWR) of the mild steel using each of the prepared lubricants were determined. Scanning electron microscopy was used to examine the worn surface of the mild steel. The results revealed that pure canola oil as a lubricant performed competitively against a blend of 80% synthetic and 20% canola oils. The viscosity of the canola oil and its various blends with synthetic oil are controlled by the environmental temperature since an increased temperature reduces the viscosity. Also, the experimental results revealed that operating parameters play the main role in controlling the wear behavior of mild steel since increasing the sliding distances increases the weight loss. The specific wear rate exhibited a steady state after about 5 km sliding distance, and different blends influenced the applied loads and velocity differently. The mixing ratio of canola and syntactic oil was not particularly significant since the pure canola oil exhibited competitive wear performance compared with the blends. However, an intermediate mixing ratio (40%–60% synthetic oil mixed with 60%–40% canola) can produce a slightly low specific wear rate among other things.
Publisher: MDPI AG
Date: 07-07-2021
Abstract: This research examines the friction and dry wear behaviours of glass fibre-reinforced epoxy (GFRE) and glass fibre-reinforced polyester (GFRP) composites. Three fibre orientations—parallel orientation (P–O), anti-parallel orientation (AP–O), and normal orientation (N–O)—and various sliding distances from 0–15 km were examined. The experiments were carried out using a block-on-ring configuration at room temperature, an applied load of 30 N, and a sliding velocity of 2.8 m/s. During the sliding, interface temperatures and frictional forces were captured and recorded. Worn surfaces were examined using scanning electron microscopy to identify the damage. The highest wear rates for GFRE composites occurred in those with AP–O fibres, while the highest wear rates for GFRP composites occurred in those with P–O fibres. At longer sliding distances, composites with P–O and N–O fibres had the lowest wear rates. The highest friction coefficient was observed for composites with N–O and P–O fibres at higher sliding speeds. The lowest friction coefficient value (0.25) was for composites with AP–O fibres. GFRP composites with P–O fibres had a higher wear rate than those with N–O fibres at the maximum speed.
Publisher: ASMEDC
Date: 2009
Abstract: In the present work, a prototype machine was developed for film thickness measurement for tribological tests. The configuration of the machine was based Block on Ring (BOR) technique. In the current machine, frictional forces and film thickness were measured using load cell and strain gauges, respectively. Calibration was made to determine the real film thickness. Experiments were conducted using the newly developed machine to investigate the film thickness during sliding of UHMWPE against aluminum alloy counterface. The tests were performed at applied loads (1.47 N–2.94 N). The results revealed that increases the applied load reduces the film thickness which in turn played a main role in controlling the surface characteristics of the polymer.
Publisher: ASMEDC
Date: 2009
Abstract: The current work is an attempt to investigate the possibility of using artificial neural network (ANN) modelling as a tool for friction coefficient prediction. The ANN model was trained at various configurations with different functions of training to develop the optimal ANN model. The experimental data was obtained from previous works. The results revealed that single layered model has reasonable accuracy in prediction when trained with TrainLM function. The results were acceptable especially in predicting steady-state friction coefficient, which proved ANN technology’s ability to predict the friction co-efficient.
Publisher: World Scientific Pub Co Pte Lt
Date: 06-2007
DOI: 10.1142/S0218625X07009487
Abstract: In this work, tribological investigations on the neat polyester (NP) and woven (600 g/m 2 )-glass fabric reinforced polyester (WGRP) composite were carried out. Friction and wear characteristics of the WGRP composite were measured in three principal orientations, i.e., sliding directions relative to the woven glass fabric (WGF) orientations in the composites. These are longitudinal (L), transverse (T), and parallel (P) orientations. The experiments were conducted using a pin-on-disc (POD) machine under dry sliding conditions against a smooth stainless steel counterface. Results of friction coefficient and wear resistance of the composites were presented as function of normal loads (30–100 N) and sliding distances (0.5–7 km) at different sliding velocities, 1.7, 2.8, and 3.9 m/s. Scanning electron microscopy (SEM) was used to study the mechanisms of worn surfaces. Experimental results revealed that woven glass fabric improved the tribological performance of neat polyester in all three tested orientations. In L-orientation, at a low velocity of 1.7 m/s, WGRP exhibited significant improvements to wear resistance of the polyester composite compared to other orientations. Meanwhile, at high velocities (2.8 and 3.9 m/s), T-orientation gave higher wear resistance. SEM microphotographs showed different damage features on the worn surfaces, i.e., deformation, cracks, debonding of fiber, and microcracks.
Publisher: SAGE Publications
Date: 07-03-2012
Abstract: For the current work, investigations were carried out using treated betelnut fibre-reinforced polyester (T-BFRP) and chopped strand mat glass fibre-reinforced polyester (CSM-GFRP) composites. Results revealed that T-BFRP showed competitive performance of about 1.16%, 17.39% and 4.92% for tensile, flexural and compression tests as compared to the latter. Through tribological performance tests, T-BFRP composite showed superiority in wear for the dry and wet tests of about 98% and 90.8% while the friction coefficient was reduced by about 9.4% and 80% respectively. The interface temperature was lower by about 17% for T-BFRP composite subjected to dry test as compared to CSM-GFRP. SEM analysis revealed that the brittle effects observed on glass fibres during the tribo test enhanced the material removal rate which increased the thermo-mechanical effects at the rubbing zone. As such, evidence of adhesive to abrasive wear transition was observed when the CSM-GFRP composite was subjected to the stainless steel counterface. On the contrary, T-BFRP composite formed a thin layer of shield (i.e. back film transfer) on its worn surface during the test, which assisted in lowering the material removal rate.
Publisher: World Scientific Pub Co Pte Lt
Date: 04-2007
DOI: 10.1142/S0218625X07009244
Abstract: In the current decade, introducing water as a lubricant for tribo-engineering materials has become a concern for many researchers. In the present study, the wear and friction characteristics of a polyester (CGRP) composite reinforced with a chopped glass mat (CSM) 450 g/m 2 was investigated under dry and wet conditions against a polished, stainless steel counterface. Two techniques known as Pin on Disc (POD) and Block on Ring (BOR) were used to perform the experimental tests. The tests were conducted on a newly developed machine that could carry out both techniques. The effects of the applied load (30, 50, 70, 100 N ), sliding velocity (2.8 and 3.9 m/s), and test duration (5–30 min) on wear rates and the coefficients of friction were investigated. Under dry conditions, the temperature of the interface was measured with an infrared thermometer. Worn surface morphologies of the composite were observed with a scanning electron microscopy (SEM) and damage features were characterized. The results showed that the test technique and conditions had significant influences on the wear and friction performance of the CGRP composite. The presence of water as a lubricant enhanced the wear and friction characteristics of the composite as determined by both POD and BOR, and the SEM micrographs demonstrated several damage features under dry/wet conditions, e.g., deformation, as well as fiber peeling, cracking, and cutting.
Publisher: SAGE Publications
Date: 03-06-2013
Abstract: Nanoclay olymer composites can be prepared by various processing techniques such as solution process, in-situ polymerization and melt blending. Each technique has an influence on the final characteristics and properties of the composites. In this study, different processing techniques are reviewed in order to study the relationship between these techniques and the final characteristics and properties of nanoclay olymer composites, i.e., the final structure formation, rheological perfection, thermomechanical and thermal properties. Thermodynamic and physical properties such as glass transition temperature, equilibrium melting point and crystallization temperature are also discussed. Moreover, the effect of ‘nanofiller’ on crystallinity phases of polymeric resin from a processing technique perspective is briefly reviewed to clarify the role of polymer-nanoclay interactions and nanoclay dispersion on the elastic-viscoelastic behaviour of composites. The current review concluded that altering processing technique (type and/or parameters) highly influences the final nanostructure morphology as well as the thermodynamic and mechanical properties of nanoclay olymer composites.
Publisher: Elsevier BV
Date: 12-2013
Publisher: ASMEDC
Date: 2008
Abstract: This paper presents an attempt to use betelnut fibres as reinforcement for tribo-polyester composites in bearing applications. The composite was fabricated using the hand lay-up technique, and contains 15 layers of randomly distributed chopped fibres and 17 layers of polyester. The adhesive wear and frictional behavior of the composites were studied against a polished stainless steel counterface using block-on-disc (BOD) machine at different applied loads (5–30N) and sliding distance (0–7km). In addition to that, the orientation of the fibre layers with respect to the sliding direction of the counterface was considered, i.e. parallel (P-O), anti-parallel (AP-O) and normal (N-O). Studies on worn surfaces, using a scanning electron microscope (SEM), and roughness profiles of the composite and counterface assisted to explain the results. As a result of this work, it was found that applied load has less effect on the specific wear rate and friction coefficient of the composite especially in P-O and AP-O. Meanwhile, in both orientations (P-O and AP-O), the steady state of specific wear rate was reached after 5 km sliding distance. On the other hand, the composite behaved differently in N-O, where the wear and friction increased when the load and sliding distance increased. This was due to the poor support of the fibres in that orientation, where delamination, pull out and breakage in the fibres were observed. In P-O and AP-O, the wear mechanism was predominated by plastic deformation and micro-cracks.
Publisher: Elsevier BV
Date: 10-2005
Publisher: SAGE Publications
Date: 17-08-2009
Abstract: This article presents an investigation on the wear and friction characteristics of oil palm fibre-reinforced polyester (OPRP) composites sliding against a polished stainless steel counterface under wet contact conditions. Two different types of OPRP composites were fabricated, which were based on treated and untreated oil palm fibres (treated oil palm fibre-reinforced polyester (T-OPRP) and untreated oil palm fibre-reinforced polyester (UT-OPRP), respectively). The experiments were conducted using two different techniques, pin-on-disc (POD) and block-on-ring (BOR), integrated into the same tribo-machine. The tests were conducted at different rotational speeds (500 and 700 r/min) and 50 N applied load for different durations (10-60 min). The specific wear rate ( W s ) and the friction coefficient were presented as a function of sliding distance. The morphology of the worn surfaces was observed using scanning electron microscopy (SEM) and the damage features were characterized. The results revealed that treating oil palm fibres has a significant effect on the wear and frictional performance of OPRP composites. Treating the oil palm fibres enhanced the wear properties of polyester by about 35-52 and 65-75 per cent in the case of the POD and BOR techniques, respectively. The observations on the worn surfaces showed various features of the damages such as debonding and breakage of fibres in the UT-OPRP composite.
Publisher: Springer Science and Business Media LLC
Date: 22-06-2007
Publisher: Elsevier BV
Date: 10-2010
Publisher: SAGE Publications
Date: 2009
Abstract: This article presents an evaluation of frictional and wear performance of new polyester composites based on coir fibres. Coir fibre-reinforced polyester (CFRP) composites were developed in a multi-layer form, mainly in three and four layers. The influence of the coir fibres on the wear and frictional behaviour of polyester was evaluated using a block-on-disc (BOD) machine under dry sliding contact conditions against smooth stainless steel. Worn surfaces of the composites were observed using a scanning electron microscope. The friction coefficient and specific wear rate were presented as a function of sliding distance (0-4.2 km) at different applied loads (10-30 N). The results revealed that all test parameters have a very significant influence on the frictional and wear characteristics of the materials. Moreover, a higher coefficient of friction was exhibited in the four-layer composite. CFRP composites based on three layers exhibited better wear and frictional performance compared with the one with four layers and neat polyester. The wear mechanism was predominated by deformation and micro-ploughing in the resinous regions and debonding of fibres.
Publisher: SAGE Publications
Date: 21-10-2009
Abstract: In the current work, the fracture toughness of sand-particle- and wood-flake-reinforced polyester composites was studied under a linear elastic fracture mechanics approach. The effects of the particulate volume fraction (0–60 vol %) were studied. Scanning electron microscopy was used to observe the damage features on the composite surface. Results showed that sand-particle- and fine-wood-flake-reinforced polymer composites exhibited better results at 40 vol % than at other particulate volume fractions. Meanwhile, coarse-wood-flake-reinforced polymer composites showed higher properties at 30 vol % than at other particulate volume fractions. Observation of the composite surface after tests showed that sand particles have poor interfacial adhesion compared with wood flakes.
Publisher: MDPI AG
Date: 14-02-2022
DOI: 10.3390/EN15041391
Abstract: Because of its potential to directly transform solar energy into heat and energy, without harmful environmental effects such as greenhouse gas emissions. Hybrid nanofluid is an efficient way to improve the thermal efficiency of solar systems using a possible heat transfer fluid with superior thermo-physical properties. The object of this paper is the study the latest developments in hybrid applications in the fields of solar energy systems in different solar collectors. Hybrid nanofluids are potential fluids with better thermo-physical properties and heat transfer efficiency than conventional heat transfer fluids (oil, water, ethylene glycol) with single nanoparticle nanofluids. The research found that a single nanofluid can be replaced by a hybrid nanofluid because it enhances heat transfer. This work presented the recent developments in hybrid nanofluid preparation methods, stability factors, thermal improvement methods, current applications, and some mathematical regression analysis which is directly related to the efficiency enhancement of solar collector. This literature revealed that hybrid nanofluids have a great opportunity to enhance the efficiency of solar collector due to their noble thermophysical properties in replace of conventional heat transfer working fluids. Finally, some important problems are addressed, which must be solved for future study.
Publisher: Elsevier BV
Date: 2010
Publisher: SAGE Publications
Date: 05-2008
Abstract: The aim of this study is to investigate the effect of treated and untreated oil palm fibres on high-stress three-body abrasive wear characteristics of polyester composites. Experimental tests were conducted at different applied loads (5–20 N) and two different rotational speeds (50 and 100 r/min) for 0.18 km sliding distance using a dry sand/steel wheel apparatus. The flow of the sand particles (560–900 μm) was 4.5 g/s. Morphologies of the worn surface of the composites were studied using a scanning electron microscope (SEM). Pull-out test was carried out to evaluate the interfacial adhesion characteristics of treated and untreated fibres. The results revealed that composites based on treated oil palm fibres exhibited better wear performance compared with untreated ones, i.e. the interfacial adhesion of treated fibres to the polyester was better than untreated fibres. Moreover, treated oil palm fibres were found to reduce the porosity of the composite, which in turn stabilized the surface tribo-characteristics. Based on the SEM analysis, the wear mechanisms were predominated by pitting, grooving, microcracking, microcutting, and fracture in the polyester region.
Publisher: Informa UK Limited
Date: 09-2011
Publisher: Informa UK Limited
Date: 06-2008
Publisher: Elsevier BV
Date: 09-2012
Publisher: World Scientific Pub Co Pte Lt
Date: 06-2009
DOI: 10.1142/S0218625X09012792
Abstract: In the current study, a multilayered polyester composite based on betelnut fiber mats is fabricated. The adhesive wear and frictional performance of the composite was studied against a smooth stainless steel at different sliding distances (0–6.72 km) and applied loads (20–200 N) at 2.8 m/s sliding velocity. Variations in specific wear rate and friction coefficient were evaluated at two different orientations of fiber mat namely parallel (P–O) and normal (N–O). Results obtained were presented against sliding distance. The worn surfaces of the composite were studied using an optical microscope. The effect of the composite sliding on the stainless steel counterface roughness was investigated. The results revealed that the wear performance of betelnut fiber reinforced polyester (BFRP) composite under wet contact condition was highly dependent on test parameters and fiber mat orientation. The specific wear rate performance for each orientation showed an inverse relationship to sliding distance. BFRP composite in N–O exhibited better wear performance compared with P–O. However, the friction coefficient in N–O was higher than that in P–O at lower range of applied load. The predominant wear mechanism was debonding of fiber with no pullout or ploughing. Moreover, at higher applied loads, micro- and macrocracking and fracture were observed in the resinous region.
Publisher: ASMEDC
Date: 2009
Abstract: In the present work, solar thermal drying system was developed. The main purpose of solar thermal drying system is to dry local vegetables and fruits. The drying system contained of two main parts as heat collector and the food drying cabinet. It is a force convection indirect type absorbing maximum solar radiation by the heat collector and provides heated air flow to the cabinet via two fans at the air inlet/outlet. The heat collector was inclined at 23.5° angle which suitable to the location for absorption of maximum solar radiation. Experiments were performed to test the efficiency of the solar heat collector and the cabinet at different daily times and operating conditions. The results revealed that 98.8°C temperature was achieved under static air condition. The air temperature at the inlet of the cabinet under both natural and forced air velocities was about 62.8°C. During the experiments, the cabinet was loaded with 426g of banana slices having an initial moisture content of 80%. The designed drying system managed to achieve a final desired moisture content of 15% within effective period of 7 hours without losing the product color.
Publisher: Elsevier BV
Date: 06-2013
Publisher: Elsevier BV
Date: 06-2013
Publisher: World Scientific Pub Co Pte Lt
Date: 27-11-2012
DOI: 10.1142/S0218625X12500655
Abstract: Roller mill is an important part of machines for preparation of agricultural food stuffs. Tribological loading is the main type of load that should be considered when investigating the design failure of roller mills or of the low quality of grinding products. In the current work a comprehensive analysis of the roller design to withstand tribological was undertaken. Three-body abrasive loading (3BA) was found to be the key element to be considered in designing the roller. High stress three-body abrasion experiments were conducted on polyester and epoxy polymers to measure the wear and frictional characteristics of the selected material, different loads, durations and sand grain sizes were tested. Scanning electron microscopy and optical microscopy were used to categorize the damage on the worn surface of the materials and the causes of failure. The current results are compared with the performance of mild steel results based on the literature. The results revealed that polyester had relatively poor wear performance compared to epoxy and steel especially when large sand grains were used. The wear mechanisms on the polyester surface were macro-pitting, fracture, ploughing and defragmentation while epoxy showed micro-pitting and defragmentation. Epoxy material performance indicates that it has potential for replacing metal rollers in the milling machine.
Publisher: Trans Tech Publications, Ltd.
Date: 04-2013
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.685.45
Abstract: Friction is classified as the main dominant element having an adverse influence on materials' lifespan and performance. Friction between any sliding contacts is continually accompanied by heat generation and shear force. The surface deterioration produces destruction in the component and reduced the life expectancy of the components. The shear force and/or the frictional heat areseen to be the main reasonscausing occurrence of the wear on surfaces and the wear removal during adhesion wear loading. In the current paper, a comprehensive experiments and observation were made to correlate the three main elements of tribology (friction, temperature, and weight loss) to epoxy and its composites based on glass and kenaf fibres. The tests were conducted in adhesive wear loading conditions against stainless steel counterface under dry contact conditions. SEM was performed to categorize the damage features of both composites. The results revealed that the interface temperature has more influence on the wear behaviour of both composites than the friction coefficient. Different destructive features were observed.
Publisher: Elsevier BV
Date: 05-2014
Publisher: Informa UK Limited
Date: 06-2010
Publisher: Elsevier BV
Date: 2013
Publisher: Elsevier BV
Date: 08-2006
Publisher: Elsevier BV
Date: 10-2011
Publisher: Springer Science and Business Media LLC
Date: 04-11-2008
Publisher: Elsevier BV
Date: 12-2013
Publisher: Elsevier BV
Date: 05-2010
Publisher: Elsevier BV
Date: 06-2013
Publisher: Elsevier BV
Date: 08-2013
Publisher: ASMEDC
Date: 2008
Abstract: This study serves to delineate the effects of material on the lifespan of a polymeric roller rubbing against a steel wire. Four materials, namely nylon, polyester, borosilicate glass and epoxy are the manipulated variables in conducting a simulation with a steel wire. A block-on-ring machine was used to conduct the tribo-experiments under dry contact condition. In concurrence with average operating conditions, the machine was set to 0.15 m/s sliding velocity, at an applied load of 10 N. Worn surfaces of the polymer were subsequently studied under optical microscopy. Frictional and wear resistance results were presented versus time for a predetermined duration. There is a strong correlation between the wear resistance and material hardness but the contrary is found with elongation at break. Findings revealed better wear resistance in epoxy due to its higher hardness. The improvement attained with reference to nylon was approximately 68%. The optical images of worn surfaces which sustained scratches and grooves implied that the contact mechanism was that of abrasion.
Publisher: World Scientific Pub Co Pte Lt
Date: 12-2008
DOI: 10.1142/S0218625X08012116
Abstract: The tribo-performance of a new engineering composite material based on coconut fibers was investigated. In this work, coconut fibers reinforced polyester (CFRP) composites were developed. The tribo-experiments were conducted by using pin-on-disc machine under dry and wet sliding contact condition against smooth stainless steel counterface. Worn surfaces were observed using optical microscope. Friction coefficient and specific wear rate were presented as a function of sliding distance (0–0.6 km) at different sliding velocities (0.1–0.28 m/s). The effect of applied load and sliding velocity was evaluated. The results showed that all test parameters have significant influence on friction and wear characteristics of the composites. Moreover, friction coefficient increased as the normal load and speed increased, the values were about 0.7–0.9 under dry contact condition. Meanwhile, under wet contact condition, there was a great reduction in the friction coefficient, i.e. the values were about 0.1–0.2. Furthermore, the specific wear rates were found to be around 2–4 (10 -3 ) mm 3 /Nm under dry contact condition and highly reduced under wet condition. In other words, the presence of water as cleaner and polisher assisted to enhance the adhesive wear performance of CFRP by about 10%. The images from optical microscope showed evidence of adhesive wear mode with transition to abrasive wear mode at higher sliding velocities due to third body abrasion. On the other hand, optical images for wet condition showed less adhesive wear and smooth surfaces.
Publisher: SAGE Publications
Date: 16-01-2009
Abstract: Fracture toughness and critical energy release rate of polyester-reinforced glass fibres were investigated using linear elastic fracture mechanics approach. The effect of fibre volume fraction of chopped strand mat glass fibres in the matrix on the composite properties was considered. Finite-element analysis using FRANC2D/L was adopted for further verification. The results showed a dramatic increase in the values of fracture toughness and critical energy release rate with increasing fibre content. 60% vf of glass fibres enhanced the fracture toughness and critical energy release rate properties of neat polyester by ∼ 22-fold and 1200-fold, respectively. The numerical results showed an agreement with experimental ones.
Publisher: Trans Tech Publications, Ltd.
Date: 02-2014
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.893.430
Abstract: In the current study, wear and frictional performances of different metals are investigated under different operating parameters against stainless steel counterface under dry contact conditions. The experiments performed using block on ring machine. Microscopy was used to examine the damage features on the worn surface and categorize the wear mechanism. Thermal imager was used to understand the thermal loading in the interface during the rubbing process. The results revealed that the operating parameters influence the wear and frictional behaviour of all the metals. Brass metal exhibited better wear and frictional behaviour compared to others. Three different wear mechanisms were observed, i.e. two body abrasion (Brass), three body abrasion (Aluminium) and adhesive (Mild Steel).
Publisher: MDPI AG
Date: 13-01-2022
DOI: 10.3390/APP12020781
Abstract: Adoption of hydrogen energy as an alternative to fossil fuels could be a major step towards decarbonising and fulfilling the needs of the energy sector. Hydrogen can be an ideal alternative for many fields compared with other alternatives. However, there are many potential environmental challenges that are not limited to production and distribution systems, but they also focus on how hydrogen is used through fuel cells and combustion pathways. The use of hydrogen has received little attention in research and policy, which may explain the widely claimed belief that nothing but water is released as a by-product when hydrogen energy is used. We adopt systems thinking and system dynamics approaches to construct a conceptual model for hydrogen energy, with a special focus on the pathways of hydrogen use, to assess the potential unintended consequences, and possible interventions to highlight the possible growth of hydrogen energy by 2050. The results indicate that the combustion pathway may increase the risk of the adoption of hydrogen as a combustion fuel, as it produces NOx, which is a key air pollutant that causes environmental deterioration, which may limit the application of a combustion pathway if no intervention is made. The results indicate that the potential range of global hydrogen demand is rising, ranging from 73 to 158 Mt in 2030, 73 to 300 Mt in 2040, and 73 to 568 Mt in 2050, depending on the scenario presented.
Publisher: Elsevier BV
Date: 05-2010
Publisher: SAGE Publications
Date: 07-2010
Abstract: In the present work, the potential of using bamboo fibres as reinforcement for polyester composites was evaluated. Two types of bamboo fibres were used: untreated and treated with different NaOH concentrations (1, 3, and 5wt%). Mechanical properties of both treated and untreated fibres were investigated. In addition, single-fibre pull-out tests were performed to study the interfacial shear strength of the fibres with the polyester matrix at different embedment length of fibres. Scanning electron microscopy was used to study the surface morphology of the fibres before and after the tests. Results revealed that an untreated fibre has the best strength and stiffness but lowest strain at break. An increase in alkali concentration reduces the strain at failure and ductility of bamboo fibres. However, the strength and stiffness of the fibres were increased. In addition, the interfacial shear strength was improved with longer embedment length and higher NaOH concentration.
Publisher: Hindawi Limited
Date: 14-08-2023
DOI: 10.1155/2023/5616909
Abstract: The agricultural industry heavily relies on machinery and equipment for efficient farming practices, but harsh environmental conditions can cause premature wear and tear, leading to financial losses. Three-body abrasion research is essential for developing more durable materials for various industries, including agriculture. Mild steel is commonly used in agricultural machinery but lacks resistance to moisture and corrosion. Slurry handling equipment is prone to wear due to abrasive particles, and red soil presents challenges for farmers. A study was conducted to investigate the wear resistance of mild steel under three-body abrasion under slurry conditions, simulating real-life agricultural environments. Different loads and operating durations were considered, and SEM was used to examine the worn surfaces. Weight loss during sliding wear was found to increase proportionally with duration and applied load. Increasing load leads to more severe wear due to higher shear forces and the formation of nucleation sites for wear particles. There is an increase in the weight loss by about 8 times when the applied load increased from 10 N to 70 N. The slurry regime and rotational speeds also affect wear rate, with higher speeds leading to deeper penetration of abrasive particles and greater impact force. The severity of wear increases with time and different wear mechanisms dominating at different durations, as observed through the SEM analysis. These findings emphasize the importance of considering load, slurry regime, and rotational speed when designing materials for sliding wear applications.
Publisher: Elsevier BV
Date: 05-2008
Publisher: MDPI AG
Date: 25-07-2021
Abstract: To reduce the emission of harmful materials into the ecosystem, researchers have been exploring the potential of manufacturing polymeric composites based on natural fibres. Although the large area of application of these materials has encouraged investigations of their performance under various loading conditions, less research has been conducted on their tribological behaviour. Hence, in this study, tribological tests were conducted on epoxy composites based on bamboo fibres. The wear performance of bamboo fibre reinforced epoxy was tested using various operating parameters, and the worn surfaces were examined using optical microscopy. The results revealed that the specific wear rate of the composites reduced since the epoxy was reinforced with bamboo fibres. Scanning electron microscopy analysis showed different wear mechanisms and damages.
Publisher: SAGE Publications
Date: 02-2010
Abstract: In the present work, an artificial neural network (ANN) model was developed to predict frictional performance of a polymeric composite. The experimental dataset at different applied loads (30–100 N), sliding speeds (300–700 r/min), and up to 10 min of sliding duration was used to train the model. The ANN model was trained with a large volume of experimental data (7389 sets). In addition to that, fibre mat orientation was considered in ANN development. Various configurations with different functions of training were used to find the optimal model. As a result of this work, single-layered models with large number of neurons showed high accuracy, up to 90 per cent in prediction, when trained with the Levenberg—Marqurdt function.
Publisher: World Scientific Pub Co Pte Lt
Date: 10-2012
DOI: 10.1142/S0218625X12500503
Abstract: In the current work, kenaf fibers reinforced epoxy (KFRE) composite was developed. Adhesive wear and frictional characteristics of KFRE were investigated under wet contact conditions at different fiber orientations, considering different applied loads (50–200 N) and sliding distances (0–30 km). Scanning electron microscopy (SEM) was used to observe the damages on the worn surfaces. The results revealed that fiber orientation plays a main role in determining the wear and frictional performance of the composites. Kenaf fibers, in normal orientation (N-O), enhanced the wear performance of the composite by about 35%–57%. It appears that the damages on the surface of the composite (N-O) were less than the other orientations (P-O and AP-O). Compared to previous work, KFRE has good potential of replacing glass fibers in tribological applications.
Location: Malaysia
No related grants have been discovered for Belal Yousif.