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Go to Editorial ManagerIn this work, four fiber Bragg gratings are fabricated by infiltration different volumes of liquids (star line Glass Mechanix optical adhesive material, olive oil diluted with ?ethanol) into the hollow core photonic crystal fibers (HC19-1550 (Thorlab Company)). The amplitude splitting interferometric technique with a high resolution specially designed translation stage was used for the fabrication process. This stage is capable of moving the fibers in micrometer ?resolution steps. The fabrication was carried out using blue laser operated at wavelength of 405 nm. The infiltrated four photonic crystal fibers were exposed to the blue laser beam of 405 nm forming periodic fringes for Bragg grating generation. These fringes were generated from the interference of two splitted laser beams. All fabricated fibers have the same Bragg length of 3.8 cm and average gratings periods of 0.224 ?m. The four fibers were analyzed by an optical microscope which displayed the areas that were cured using blue laser. The fabricated fibers also were tested by putting laser beam at one end of the fiber and determining the transmittance at the other fiber end by optical signal analyzer? (Thorlabs-CCS200). The resulted Bragg grating fibers have 653.3 nm Bragg reflected wavelength. The results also showed that fiber with higher volume of olive oil has the highest reflection peak about ?96.09647 %? with the greatest FWHM (full width at a half maximum) ?about 0.74 nm.In addition, three of the fabricated fibers (B, C and D) that contained olive oil were prepared for testing magnetic field sensor. The results show that all the fibers shifted to near infrared range. The results also showed that fiber with higher concentration of olive oil has the greatest magnetic wavelength shift about 653.4 nm, the highest fiber sensitivity about ??0.000494623656 nm/ Gauss?, the highest reflection peak about 96.91827? %, and the greatest FWHM ?about 0.98 nm.
In this research, binary blends have been prepared from epoxy resin (EP) and different weight percentages of polysulfide rubber (PSR) (0%, 2.5%, 5%, 7.5 and 10%), and then compression, impact, and hardness tests were evaluated. The experimental results showed that the addition of polysulfide rubber in the epoxy resin decreased the compressive strength, Young's modulus, and hardness, while increased the impact resistance. It was found that the weight percentage 5% of polysulfide was the best percentage, which gives the best mechanical properties for the blend matrix. The advantage of this blend matrix is that, it mediates between the brittle properties of epoxy and the flexible properties of a blend matrix with the highest percentage of PSR. Short fibers (Carbon & Glass) with different volume percentage (2.5%, 5%, 7.5%, and 10%), were used to reinforce the best blend matrix obtained separately and randomly, and then the same mechanical tests conducted on these composites. The experimental results showed that the addition of fibers increased the compressive strength, Young's modulus, impact resistance and hardness. It was also observed that the composites materials reinforced with carbon fibers have significantly higher mechanical properties values than the composites materials reinforced with glass fibers.
In this work chopped carbon fibers are used to improve tensile strength of Porcelanite lightweight aggregate concrete. Silica fume was added in order to improve the mixes compressive strength. Silica fume increase water demand and using fibers reduce workability, to improve workability and decrease water demand high rang super plasticizers are used. The results showed that compressive strength, splitting tensile strength, modulus of elasticity of carbon fibers Porcelanite lightweight aggregate concrete increase with increasing of carbon fiber up to 2% compared to reference Porcelanite lightweight aggregate concrete without fibers. The percentages of increasing were 14.40%, 68.00%, and 10.66% for compressive strength, splitting tensile strength, and modulus of elasticity, respectively. Flexural Strength continues in increase with increase of fibers. The dry unite weight of mixes with chopped fiber decrease with increase of fiber percentage. Besides the chopped carbon improved the ductility of Porcelanite lightweight aggregate concrete and that clear from stress-strain relationship.
Photonic crystal fibers (PCFs) are generally divided into two categories: solid-core photonic crystal fibers and hollow-core photonic crystal fibers. In this paper, a long-period fiber Bragg grating (LPFBG) was experimentally fabricated in a hollow-core photonic crystal fiber (HC-PCF) using a CO₂ laser and based on the point-by-point technique. Proper LPFBGs were inscribed using laser powers of 0.9 W and 1.4 W, with grating parameters (grating period, length of each pitch, and depth of each pitch) equal to (136 µm, 48.042 µm, 16 µm) and (142 µm, 74.027 µm, 22.09 µm), respectively, for two samples. The Bragg wavelengths and full-width at half-maximum (FWHM) were (1529.274 nm, 1.34 nm) and (1529.629 nm, 5.11 nm), respectively, for the two samples fabricated using CO₂ laser powers of 0.9 W and 1.4 W. From these results, it was recognized that the optimal LPFBG-HC-PCF was the one fabricated using 0.9 W laser power. The unique structure of hollow-core photonic crystal fibers, which enables light propagation within the air core and provides a large internal surface area, has attracted significant research interest for various sensing و communication applications, Environmental and Biological Monitoring, and medical applications.
In this work, waste glass powder from broken windows and plastic fibers from waste polyethylene terephthalate bottles are utilized to produce an economical self-compact concrete. Fresh properties (slump flow diameter, slump Flow T50, V. Funnel, L–Box), mechanical properties (Compressive strength and Flexural strength) and impact resistance of self-compact concrete are investigated. 15% waste glass powder as a partial replacement of cement with five percentages of polyethylene terephthalate plastic waste were adopted: 0% (reference), 0.5%, 0.75%, 1%, 1.25% and 1.5% by volume. It seems that the flow ability of self-compact concrete decreases with the increasing of the amount of plastic fibers. The compressive strength was increased slightly with plastic fiber content up to (0.75%), about 4.6% For more than (0.75%) plastic fiber. The compressive strength began to decrease about 15.2%. The results showed an improvement in flexural strength and an impact on the resistance in all tested specimens’ content of the plastic fibers, especially at (1.5%) fibers.
Electrospinning is a simple and highly versatile method for generating ultrathin fibers (mainly polymers) with diameters ranging from a few micrometres to tens of nanometres. This technique has attracted tremendous recent interest in both academia and industry, owing to its unique ability to produce ultrafine fibers of different materials in various fibrous assemblies. Electrospinning is a process that uses an electric potential to overcome the surface tension of a solution to produce an ultra-fine jet, which elongates, thins and solidifies as it travels through the electric field to a collector.. In this research, we studied the effect of conditions of the cabin “specifically humidity” on the diameter of nanofibers manufactured by electrospinning. We used Polyvinyl alcohol (PVA) polymeric solution with weight concentration of 10%, voltage 20 kv, under different values of relative humidity. Fiber morphology and fiber diameter were determined using scanning electron microscope, and measuring the fiber diameter by using image j program. It was found that the diameter of the fibers increased with increasing the relative humidity within our studying area .
Normal concrete is weak against tensile strength, has low ductility and also insignificant resistance to cracking. The addition of diverse types of fibers at specific proportions can enhance the mechanical properties as well as the durability. Discrete fiber, which is commonly used, have many disadvantages such as balling the fiber, random distribution, and limitation of the used Vf ratio. Based on this vision, a new technique was discovered, enhancing concrete by textile-fiber to avoid all the problems mentioned above. This paper presents all important consequence and conclusions obtained from previous studies on how to strengthen concrete with two-dimensional and three-dimensional textile-fibers, and focuses on the flexural behavior of concrete members. The results indicate that there was an improvement in flexural strength, deformation capacity, and toughness with different load conditions when using different types of textile-fiber. It was observed that the effect of textile-fibers would increase when this fiber was coated by epoxy. In TRC system, there is a significant impact on the number of textile-fiber layers used.
Soil reinforcement techniques have been successfully used to improve the shear properties of weak soils in recent years. To improve the utilization of waste resources and promote sustainable development of infrastructure amid rapid urbanization, one potential option for reinforcement materials is human hair fibers (HHF). Because it is a natural fiber, there are risks to human and environmental health associated with the improper disposal of human hair fiber, an occurring waste product that does not decompose completely. This fabric is abundant, has a high reusability rate, and is ideal for use as a reinforcement to address waste management issues and make the most of inefficient or unnecessary manufacturing websites for long-term sustainability. The CBR test was executed on several samples with diverse fiber possibilities to evaluate the engineering properties of the randomly placed HHF in clayey soil samples using fibers whose average length was 50 mm and whose diameter ranged from 60 to 80 microns and compared the outcomes to those of unreinforced soil. The soil sample was treated with different percentages of Human Hair fiber (0%, 0.75%, 1.5%, 1.75% and 2.25%). The results showed that the value of CBR of the soil sample decrease at 0.75% of HHF and then increased up to 2.25% of HHF.
The purpose of this study is to reduce weight and improve the mechanical properties of aircraft wing using Hybrid materials known as fiber metal laminates (FMLs). In this study, seven layers were used to produce the FMLs that consist of aluminum alloy2024-T3 reinforced by carbon and glass fibers bonded with blend of epoxy-resole. The Carbon Glass Reinforced Aluminum Laminates (CAGRALLs) was used as FMLs. The results showed that The CAGRALLs gave good mechanical properties because of increasing in tensile strength, elongation at fracture and impact toughness except flexural strength by comparing with other FMLs using commercial epoxy. The increasing in layers led to weaken adhesion force between layers of FMLs caused decreasing almost mechanical properties. The FMLs has good mechanical properties by using carbon and glass fibers by comparing with carbon and jute fibers. The CAGRALLs have higher numbers of cycles at failure under cyclic loadings than Aramid Reinforced Aluminum Laminates (ARALLs). The CAGRALLs have lower density by comparing with aluminum alloy 2024-T3 that used in manufacturing of aircraft wing.
The non-woven materials industry is one of the fastest-growing industries in the world with the ability to produce materials in less time, specifications, and better prices. nonwoven materials are defined as a web of guided or random fibers that are bonded by friction, interlacement or adhesion. In this research, the rotary electrospinning system was used and a prototype was made to study the process and the complete visualization in terms of the correlation of the electrostatic forces to the formation of nanofibers by preparing polymeric solutions and exposing them to the electric field between the positive electrode (the serrated cylinder) and the Grounded electrode (plate) and produced high-precision fibers with a diameter (185nm) at 25 kV, whereas the installation of polyvinyl alcohol (PVA) was with different concentrations and the formed fibers possessed an effective surface and deposited on a collector electrode forming nonwoven webs and high productivity is the most important feature of this system compared with the traditional electrospinning system.
Consider polymers and polymer matrix composite are the basis of the most prevalent material in all industrial and medical fields because of its properties qualify to occupy an advanced position among other engineering materials because of its good properties._x000D_ Therefore, This work focuses on the preparation of base polymer matrix composite materials and study non-saturated polyester as matrix has been strengthened by zeolite particles different grain sizes (25 - 65 - 75) µm and different volume fractions (1,5 - 3 - 4,5 - 6 - 7,5 - 10) % was strengthened by Carbon short fibers and constant volume fraction (8%),the tests tensile and bending according to ASTM specifications, respectively. Through the results it was observed that the maximum tensile strength improved through hybrid reinforcement when reached the maximum value when the grain size (25 µm ) and at volume fraction (7.5%), reaching ( 94 N/mm2 )compared with the rest of sizes and at the same volume fraction reaching (78 N/mm2 for 65 µm , 69 N/mm2 for 75 µm), As for the bending test has been getting maximum Flexural resistance at grain size (25 µm) at volume fraction ( 6%) reached to(111 N/mm2) ,if compared with the rest of sizes at the same volume fraction reaching (100 N/mm2 for 65 µm,79 N/mm2 for 75 µm) while was obtained on the maximum bending modulus at grain size (25 µm) and at volume fraction (10%) reach to (8099 N/mm2) if compared with the rest of sizes at the same volume fraction reaching (7466 N/mm2 for 65 µm, 6666 N/mm2 for 75 µm ). Through the results we note that for the particle size and fiber effect in improving the mechanical behavior of the composite material prepared.
This research submits theoretical and experimental realization of shear behavior of RC I-beams with polypropylene fiber with different volume fraction of plastic fiber as additive. The enhance of the sustainability of structural elements through the development of its mechanical performance by adding new materials such as plastic raw materials has become more important in the current period , particularly I- beams that was used in the long spans structure to become more environmentally-friendly. Seven specimens were tested in this study and only the amount of fiber volume fraction was varied. Experimental results showed that the ultimate strengths are increased in range (4.4% to 35.27%) that of control IB-1 for the tested beams containing Polypropylene Fiber Reinforced Concrete (PPFRC) with varied amount percentage of fiber material. Crack arrest mechanism of polypropylene fibers, and compressive strength of concrete increased in range (7.42% to 29.3%) that of plain concrete, and improved the tensile response in range (8.36% to 92.7%) that of plain concrete, limited crack propagation. So, improved behavior was obtained._x000D_ ANSYS 11, Finite Element models software are used to emulate two tested I-beams. 3D - nonlinear solid elements was utilized to model the concrete, while, the steel reinforcement was demonstrated by spar element. It was found that the general practices of the FE models demonstrated acceptable concurrence with perceptions and information from the experimental tests.
In this paper the ability of fabricating laminate composites by manual layup was discussed. Heating method was used to manufacture the composites; heat was applied to approximately 12 hours with specific heat temperature. There were four types of laminate composites fabricated and studied in this research, containing Aluminum alloy 6061 as the common element in all types, two types of fibers; woven Carbon fiber with two different orientations: ±45°, ±60°, random fiberglass and with two types of resin; epoxy resin and polyester resin. Different types of composites were made to determine the effect of CNC milling machine to the measured surface roughness and for specified parameters. The weight fraction ratio of the fibers is 37%, polymer is 34% and 29% for Aluminum. The parameters selected are spindle speed, feed rate and depth of cut. The L9 Taguchi orthogonal arrays, signal to noise (S/N) ratio and analysis of variance (ANOVA) are selected to determine the effect of these parameters; it was analyzed by MINITAB 17 program. The results showed that the parameter were significant more to the epoxy resin specimens than polyester resin specimens. The optimal milling parameters for good surface finish for Aluminum – Carbon fiber composite are at 3000RPM, 1200mm/min, 1.2mm, and for Aluminum – Fiberglass composite are 5000RPM, 1800 mm/min, 2.0mm.
Eight RC circular hollow columns (external diameter = 220 mm, internal diameter = 100 mm, length = 1000 mm and the hollow part = 700mm) casted and strengthened with ferrocement fibers composites to illustrate the behavior of these columns under concentric and eccentric axial compression force. Two columns where used as reference columns, which were repaired after failure to be tested as retrofitted columns. Six specimens were strengthened with one and two WWM layers as required. The variables considered included number of the WWM layers (N), the loading configuration and the eccentricity value (e) of loading. The ferrocement thickness was constant at 20 mm in all retrofitted and strengthened specimens.The test results revealed that the maximum increase in the ultimate concentric loads were 67% by strengthening the reference column with two layers of WWM, and the maximum increase in the ultimate eccentric load of columns was 78% by increasing of the WWM from one to two layers. For a constant number of WWM layers, the change from concentric to eccentric force caused a decrease in the ultimate load value attaining 73.5% for one- layer WWM strengthened columns. The failure of columns occurred by yielding of steel reinforcement followed by concrete crushing (i.e. tension failure).
Recently, considering polymer composite in manufacturing of mechanical parts can be caused a fatigue failure due to the very long time of exposure to cyclic loading and may at environmental temperatures higher than their glass transition temperature; therefore, in this paper, a comprehensive investigation for bending fatigue behavior at room and elevated temperatures equal to 60 °C, 70°C, and 80 °C will be done. Rotating bending test machine was manufactured for this purpose supplied with a connected furnace to perform fatigue tests at elevated temperatures. The obtained results appeared that the increase in applied stress and temperature caused a clear reduction in fatigue life; also the addition of carbon nanotubes enhanced the fatigue life at different temperatures by 183%, 205%, 218%, and 240%, respectively while the addition of short carbon fibers improved fatigue life by 324%, 351%, 387%, and 415%, respectively. As well as, Polyamide 6,6/carbon fiber composite appeared fatigue limit at temperatures equal to 20°C and 60°C and stresses approximately equal to 55 MPa and 38 MPa respectively.
A theoretical and experimental investigation pertaining to the buckling behavior of slender fiber reinforced polymer columns subjected to axial loading under varying temperatures (from room temperature to 50?). Two groups of composite materials were used for manufacturing of test specimens, the first consist of perlon fiber as a reinforcement and acrylic resin as a bonding matrix, while the second consists of a combination of perlon and carbon fibers as reinforcement. The composite specimens were fabricated by vacuum molding technique and cut according to ASTM D-638 for conducting tensile test. The data from tensile test were used to calculate the effective slenderness ratio and defining the column as Euler buckling column. An experimental rig was designed, manufactured and calibrated to study the effect of thermal and buckling load subjected to columns.Numerical analyses pertaining the buckling behavior for both groups were conducted. The results show that the temperature has a considerable effect on properties of fiberreinforced polymer composites where the value ofcritical load and Young's Modules decrease withthe increase of temperature for both groups.Perlon & Carbon reinforcement composites gavebest mechanical properties, which make them thebest candidate to improve the buckling resistancecharacteristics of composite materials.
This study involves the addition of nano silica (NS) with average particle size 12nm, micro high reactivity mitakaaolin (MHRM) particle size ? 0.554 ? 1.271 µm, micro ground granulated blast-furnace slag (MGGBFS) particle size ? 0.365 <2.932 µm and micro carbon fibers, the length of the fiber 8.5 mm and a diameter of 0.001 mm to cementations mixtures to investigate their effect on the impact strength with used magnetic water or normal water in mixing blends._x000D_ The results have shown that cementitious mixtures used in the mixing magnetic water containing 10% MGGBFS, 10% MHRM or 2.5% NS and reinforced with 2% micro carbon fiber have improved greatly in impact strength as the absorbed energy to the emergence of the first crack at age 28 days reaches to (231.55, 209.49 and 199.49) kN.m respectively, whereas for the reference cementitious mixtures it has been 1.574 kN.m
thetic socket, is due to its fiber strength and hardness, and low cost, but there are other more important things which must be considered than these specifications which are1the health1and safety. In this research fiberglass is replaced with monofilament fiber in order to be safe to on makers and users of this socket. In this paper two models of lamination manufacturing have been made and compared in terms of mechanical properties and fatigue life. The first is available and consists of: (4 perlon, 2 fiberglass and 4 perlon), The second is proposed lamination which consists of: (4 perlon, 1 cotton, 1 monofilament and 4 perlon). Simulations were conducted on the made socket made of two types of lamination by using ANSYS 14.5 to show the distribution of stresses, the amount of deformation and less safety factor for both cases. The results show an increase of 42% in the Young's modulus and a decrease in tensile stress and yield stress by 10.8% and 46% respectivel, As for the stress endurance it witnessed an increase of 140%.The simulation results show a decrease in the deformation by 40.7% and an increase in the minimum value of the safety factor of 0.323 to 1.05.
The purpose of this research is to investigate how the fiber orientation and loading axis of a composite material affect its behavior. Consideration was given to two different fiber-to-matrix ratios in order to improve the mechanical properties. Hand lay-up samples were produced in accordance with ASTM D790 for flexural testing. On UTM, tensile and flexural tests were performed on the sample. The effect of fiber orientation modifies the composites' mechanical properties. As the fiber orientation increased, the tensile strength of the composite would reduce. This carbon/epoxy composite test demonstrates better strength than those conducted at (30, 5, 60, and 90 degrees). For flexural tests, a three-point bend at 30 degrees demonstrates excellent strength. Utilizing the three-point bend method, the flexural strength and flexural modulus have been determined. The tensile strength, young's modulus, elongation percentage, maximum load to break the composite, peak load, and flexural strength of single- and double-layered carbon fibers were compared and examined. As the number of layers increased, the adhesion between layers of epoxy and fiber carbon, and glass fiber weakened, causing a decrease in almost all mechanical properties. The fabricated 2024-T3 and epoxy glass fiber had higher fatigue strength than aramid reinforced and lower density than steel alloy utilized in aircraft manufacture.
In this paper, the cross section behavior of reinforced concrete columns made of normal and hybrid reactive powder concrete (hybrid by steel and polypropylene fibers) under concentric and eccentric vertical load was study. The casted columns were cured in two different type tap water for 28 days and chloride water for six months. Chloride salts with concentration was 8341.6 mg/l. Three variables were adopted in the experimental program; concrete type, curing type and the eccentricity of vertical load. Twenty (120x120x1200) mm columns were casted and tested depending on these variables. The different eccentricities were (0, 50,100 and 150) mm and where (e/h) were (0, 0.42, 0.83 and 1.25) respectively from the center of column, the other types of loading are tested the specimens as beam._x000D_ The experimental results showed increasing in ultimate load capacity and higher chlorides resisting for hybrid reactive powder concrete in comparison with normal concrete in both types of curing (tap and chloride water). Through studying load deflection, test results for Normal Strength Concrete (NSC) and Hybrid Fiber Reactive Powder Concrete (HFRPC) columns that deflection for columns cured in chloride water more than tap water when compared at the same load that also by increase eccentricity leads to an increase in deflection for both cured and The neutral axis depth for HFRPC columns is more than NSC at the same load also when eccentricity increases, the compression zone decreases and neutral axis also decrease by increase eccentricity. These results occur when columns are cured in tap and chloride water._x000D_
Whispering Gallery Mode Micro-Resonators (WGMRs) have received significant interest due to their great sensitivity to environmental changes, compact size, and ability to operate over a wide spectral range because their low optical losses produce high-quality factors so that they can be used in various sensing applications. This work investigates the design and implementation of cylindrical WGMRs for Refractive Index (RI) sensing for different delivery fiber diameters. Single Mode Fiber with different waist diameters (80,67.1,18) µm were used as delivery fibers. At the same time, the sensor (resonator) fiber is SMF with a diameter (125 µm). Quality factors and Free Spectral Range (FSR) were calculated and analyzed for each diameter. The quality factor for all diameters was in power of 104, which is considered good. The FSR is inversely proportional to fiber diameter. FSR values were (0.678,1.75,2.03) nm for (80,67.1,18) µm delivery fiber diameters respectively. An analyte prepared by NaCl with different refractive indices is used to investigate the RI sensor performance. Higher sensitivity is obtained from the WGMR with a smaller waist diameter, which is (-)74 nm/RIU. While for the delivery fiber diameters (80,67.1) µm were (-0.28, -9.27) nm/RIU respectively. The submitted sensor will have a good contribution in the field of chemical, biological and medical applications.
Lightweight foamed concrete (LWFC) is characterized as a light in self-weight, self-compacting, self-levelling, and thermal and sound isolation. But it has low strength and low ductility which leads that the application of (LWFC) in the building construction is limited. The flowability of the fresh mix of (LWFC) was evaluated by flow test. While the hardened properties of (LWFC) include, compressive6 strength, tensile6 splitting6 strength, flexural6 strength, and 6modulus of 6elasticity. This6 study6 focuses6 on the effect of the adding of silica fume and steel fibre on the mechanical properties of (LWFC). Silica fume was added as (5%) and (10%) by the weight of cement and steel fiber (0.2%) and (0.4%) of the total volume of the mix. The density of lightweight foamed concrete was 1800±50kg/ , and cement to sand ratio was (1:1) with water cement ratio (0.28). The results indicated that adding of silica fume6 and steel6 fiber6 have great effect on the mechanical properties and improve them. The addition (10%) of silica fume and (0.4%) by volume of steel fiber was the best ratio that improves the mechanical properties of the lightweight foamed concrete (LWFC). The pozzolanic index of the (5%) and (10%) silica fume was (21.9%) and (74.76%), respectively.