1- Abstract

This paper experimentally investigates the flexural and tensile properties of the industrial wastes sewage sludge ash (SSA) and fly ash (FA), and conventional ceramic powder silicon carbide (SiC) filled polyester composites. Four weight fractions (5, 10, 15 and 20 wt%) for each micro filler were used for production of composites. Then, test samples were produced according to ASTM. The resulting degree of particle dispersion in the polymer matrix was visualized by using scanning electron microscope (SEM). Results from this study showed that the tensile strength increased up to its maximum value at filler content 5 wt% of SSA, FA and SiC. Flexural strength increased with addition of particulate filler up to its maximum value at filler content 5 wt% of SSA and FA, while for SiC decreased for all weight fractions gradually. The addition of SSA, FA and SiC fillers resulted in increase of tensile and flexural modulus for all the particulate composites. Industrial waste SSA can be used as an additive with polymer to produce composite materials.

2- Abstract:

 Fracture toughness of particle filled polymer composite beams with different particle content for varying of crack inclination angles was investigated in mode I and mode III loading conditions. The beams were tested using three point bending test with crack inclination angles of 30°, 45°, 75° and 90°. Sewage sludge ash (SSA), fly ash (FA) and silicon carbide (SiC) micro particles were used as toughening fillers with 5, 10, 15 and 20 wt% contents of the total weight of the polymer composites. The Scanning Electron Microscope (SEM) micrographs showed that a good indication was observed for dispersion of FA, SSA and SiC particles within the polymer matrix. The critical crack tip stress intensity factors K_Ic (crack angle 90°) and K_IIIc, and the critical strain energy release rates G_Ic and G_IIIc were calculated and their results were compared. The mode I and mode III fracture toughness of particulate polyester composite were improved by addition of particulate fillers. The maximum values of fracture toughness mode I (K_Ic and G_Ic) and mode III (K_IIIc and G_IIIc) were recorded at particle content of 5 wt% polymer composites.

3- Abstract

The present paper investigates the interlaminar shear strength (ILSS) of the woven carbon, glass, and Kevlar fiber reinforced epoxy (CFRE, GFRE and KFRE) composites filled with SiC particles. The work covers the samples preparation, testing and analyzing. The samples were fabricated using the regular addition of the SiC particles as 0, 5, 10, 15, and 20 wt% of the total weight of epoxy resin. Samples of the short beam shear (SBS) test were cut using CNC machine. The experiments were conducted according to the ASTM-D-2344 standard. The fracture surfaces of the laminate samples were observed by scanning electron and optical microscopy. The major benefits of the current study are that the modification process by adding a certain amount of the SiC particles significantly enhanced the interlaminar shear strength of CFRE, GFRE and KFRE composites as the comparison to the conventional ones.

4-Abstract

The aim of this study is to investigate the hybridization effects of intraply carbon/aramid fabric layers with S-glass fabric layers on the tensile and flexural behavior of asymmetric and symmetric arrangements of hybrid composite laminates. The results revealed that the replacement of some carbon/aramid fiber layers with S-glass fiber layers in the composite laminate can provide enhancements in tensile strain, tensile modulus and flexural properties while the tensile strength results were slightly degraded. Three-point bending test results indicated a significant improvement in flexural properties when S-glass fibers employed in compressive side across the depth of composite laminates. The maximum increment in tensile modulus, flexural modulus and flexural strength of hybrid composite laminates were 19.7%, 50.0% and 42.3%, respectively compared to carbon/aramid fiber reinforced epoxy composite.

5-Abstract

This study explores the influences of laminates stacking sequence configuration on the mechanical behavior of hybrid composites. The woven carbon, Kevlar and S-glass fibers with epoxy resin were used to produce the hybrid composite specimens in addition to full composites. The hybrid specimens were prepared by introducing different fiber volume fractions between carbon/glass, carbon/Kevlar, glass/Kevlar and carbon/glass/Kevlar fibers. Stacking sequence and fibers in outer skin of the laminates were obviously shown the effective influence of tensile and flexural strength with modulus. The maximum change in tensile strength due to hybridization effect was achieved with carbon/glass epoxy laminate by replacing the two face sheets of the carbon fibers with glass fibers, resulting in increase of tensile strength by 60 % according to full carbon/epoxy laminates. On the other hand, flexural strength of glass/Kevlar hybrid laminates showed the highest hybrid effect, resulting in 78 % increase according to full Kevlar/epoxy composites.

6- Abstract

The present paper investigates the interlaminar shear strength (ILSS) of the woven carbon, glass, and Kevlar fiber reinforced epoxy (CFRE, GFRE and KFRE) composites filled with SiC particles. The work covers the samples preparation, testing and analyzing. The samples were fabricated using the regular addition of the SiC particles as 0, 5, 10, 15, and 20 wt% of the total weight of epoxy resin. Samples of the short beam shear (SBS) test were cut using CNC machine. The experiments were conducted according to the ASTM-D-2344 standard. The fracture surfaces of the laminate samples were observed by scanning electron and optical microscopy. The major benefits of the current study are that the modification process by adding a certain amount of the SiC particles significantly enhanced the interlaminar shear strength of CFRE, GFRE and KFRE composites as the comparison to the conventional ones.

7- ABSTRACT

The effects of perlite particulate-filler on the mode I and mode II interlaminar fracture and mechanical behavior of glass fabric/epoxy composites were studied. Composite specimens for double-cantilever beam (DCB), end-notched flexure (ENF) tensile and flexural tests were prepared and tested according to ASTM standards with perlite contents of 1, 3, 5 and 10 wt%. The optical and scanning electron microscopes images were described the mechanisms of mode I and II interlaminar fracture. The results indicated that the mode I and mode II interlaminar fracture toughness were optimum at perlite content of 3 wt% with increment of 39.9% and 72.3%, respectively. The tensile strength and flexural properties reached maximum values at perlite content of 1 and 5 wt%, respectively.

8- ABSTRACT  

The effect of the content of micro-scale natural pistachio shell particles on the mechanical properties of polyester matrix composites was experimentally investigated. The pistachio shell particle contents were 0, 5, 10, 15, 20 and 25 wt%. Tensile, flexural, and Charpy impact tests were carried out on molded composite specimens according to the ISO 179/92 standard. Good dispersion of pistachio shell particles in polymer matrix was observed using SEM micrographs. The highest tensile strength, flexural strength, and impact strength was obtained at a pistachio shell particle content of 10, 5, and 5 wt%, respectively.

9- Abstract.

Present study compares the tensile and impact characteristics of Kevlar, carbon and glass fiber reinforced composites with addition of microscale silicon carbide (SiC) within the common matrix of epoxy. The variation of tensile and impact strength values was explored for different content of SiC in the epoxy resin by weight (0, 5, 10, 15 and 20 wt%). Resulting failure characteristics were identified by assisting charpy impact tests. The influence of interfacial adhesion between particle and fiber/matrix on failure and tensile properties was discussed from obtained results and scanning electron microscopy (SEM) figures. It is concluded from results that the content of SiC particles, and fiber types used as reinforcement are major parameters those effecting on tensile and impact resistance of composites as a result of different interface strength properties between particle-matrix and particle fiber.

10- Abstract.

In this study, influence of micro-scale particles (borax, perlite, and sewage sludge ash) on tensile and impact resistance of S-glass/epoxy composite laminates was experimentally investigated. During the production of test samples, epoxy resin was modified incorporating inorganic and waste fillers with different weight ratios (0, 5, 10, 15 and 20 % for borax, and 1, 2, 5 and 10 % except for perlite). Damage mechanisms and impact properties of particle modified composites were characterized by charpy impact tests. Results showed that incorporation of particulate fillers in the S-glass/epoxy composites revealed the significant increase in tensile and impact resistance up to the critical particle loading, and then following the decreasing trend due to the decreasing of interfacial strength between matrix-particle-fiber interactions.

11- Abstract.

The effects of nano-silica (NS) particles inclusion on the tensile, flexural, vibration and damping characteristics of intraply and woven fiber reinforced carbon/Kevlar/epoxy (CKFRE) hybrid composites were experimentally investigated. Test samples were prepared according to ASTM standards for five different weight contents of NS particles (0.5, 1, 1.5, 2.5 and 3 wt%). Experimental modal analysis was performed only for fundamental frequency to measure damping and natural frequency for characterization of vibration properties. Results showed that 20 % improvement in tensile strength was seen at NS content of 3 wt%, while flexural strength was increased by 35.7% according to unmodified CKFRE samples. It was concluded that interaction of NS particles with epoxy and fiber leading to improve interfacial stress resulted in a significant effect on dynamic properties in terms of natural frequency and damping ratio.

12- Abstract

In the present contribution, the impact properties of clay and silica nanoparticles for strengthening an intraply carbon/aramid fiber reinforced epoxy composite have been investigated. Five clay and silica nanoparticles, containing 2, 4, 6, 8 and 10 wt.-% and 0.5, 1.0, 1.5, 2.5 and 3.0 wt.-%, respectively, were used to produce the hybrid composite specimens. The Charpy impact results indicate that the impact energy and strength were improved for all clay and silica nanoparticles specimens, as compared to the unmodified carbon/aramid fabric reinforced epoxy composite. The images of the damaged specimens show a significant fiber pullout with delaminated layers at the impacted and edge surfaces. SEM investigations revealed a good interfacial adhesion of the clay and silica nanoparticles to the carbon/aramid fiber reinforced epoxy composite.

 1- Abstract

This research focuses on the preparation of polymer matrix composite material by (hand lay – UP) method, where the material was prepared from unsaturated polyester resin (up) as a matrix reinforced by natural jute fiber with different volume fractions (3%, 4%, 5%, 6%).The experimental work and finite element techniques were used to analysis the tensile and the buckling analysis of the composite beam reinforced by natural jute fiber at different volume fraction.

The results of experimental work of the modulus of elasticity were in the range of the theoretical results. The critical load increased with increase the fiber volume fraction that (=610N) at (= 3%) and (=830N) at (=6 %) for the experimental results.While (=619N) at (= 3%) and (=877N) at (=6 %) for the finite element results.

2- Abstract

This research includes experimental and numerical analysis using finite element method by ANSYS11 package to study effect of reinforcement of Aluminum –Silicon with ceramic particles (Alumina) for different beam width (12, 14 and 16mm) on the hardiness and bending properties.

The composite material is produced using the vortex technique by cutting the base alloy to small pieces and put inside steel crucible. Put the steel crucible inside gas furnace in temperature (700^oC). The electrical mixer used to vortex the mixture and adding the aluminum oxide particles (Alumina) (5% and 10%) and after that pouring the melting in metallic mold.

The results of the study showed that Vickers micro hardness increased from (HV=105) for pure Aluminum –Silicon alloy to (HV=127) with (10%) Alumina, also the tensile strength increased from (95 Mpa) to (135 Mpa). The maximum flexural strength was (451 MPa) and the maximum shear stress was (33 MPa) at (width=16 mm) with volume fraction (10 %) of Alumina. the maximum strain decrease with increase volume fraction of Alumina. The experimental and finite element results obtained are approximately agreement.

3- Abstract

Experimental work and finite element techniques were used to analyze the tensile and buckling characteristics of carburized low carbon steel columns for different diameters.

The back of carburization consists of hardwood charcoal mixed with barium carbonate as the energizer. The specimens were carburized using (30%) of energizers at temperature equal to (900ºC) for 5 five hours.

The modulus of elasticity as measured experimentally was used in FEM (ANSYS) to calculate the buckling load. The results of the study showed that the Vickers micro hardness increased from (HV=210) to (HV=525), the tensile strength increased from (708 MPa) to (1065 MPa) and critical buckling load increased from (18.37 kN) to (19.6 kN) for d=8mm. Also critical buckling load increased from (5.8 kN) to (19.2 kN) as the diameter of the carburized low carbon steel column increased from 6mm to 8mm respectively for FEA analysis.

4- Abstract

This research focuses on the preparation of polymer matrix composite material by (hand lay – up) method, where the material (rectangular beam) was prepared from unsaturated polyester resin as a matrix reinforced by natural jute fiber with different volume fraction (3%, 4%, 5%, 6%).

Numerical studies by using finite element method (Ansys 11 package) to study the effect of selected volume fractions of jute fibers on the bending properties.

Results of this experimental research indicate that increasing the volume fraction of jute fibers lead to increase bending modulus of elasticity.

The values of flexural strength and shear stress increase with the increase of jute fibers volume fraction while the values of deflection and maximum strain decreases for both experimental and numerical studies.

5- Abstract

This research includes experimental and numerical studies by using finite element method to study the effect of carburized low carbon steel for different beams width on the hardiness and bending properties.

The back of carburization consists from hardwood charcoal mixed with barium carbonate as the Activator. The specimens were carburized using (30%) of Activator at temperature equal to (900ºC) for five hours.

The modulus of elasticity obtained from experimental work used in FEM (ANSYS) to calculate flexural strength, maximum strain and maximum shear stress and these results increase with carburized low carbon steel. The results of the study showed that the Vickers micro hardness increased, the maximum flexural strength (1750 MPa) and maximum shear stress was (121.5 MPa) at width (16 mm) for the experimental results carburized low carbon steel. The experimental, finite element and analytical results obtained for the bending analysis are approximately agreement.

6- Recycling of Sewage Sludge Ash in Polymer Structures

Abstract

In this study sewage sludge ash (SSA) particles were used as filler in the polyester resin to fabricate particulate composites with various filler contents of 0, 1, 2, 3, 4, 5, 6 and 7 wt%. The tensile, flexural, impact, hardness, chemical composition and scanning electron microscope tests wear conducted on the samples according to ASTM standards. The results indicated that the tensile and flexural strength increased at the particle content of 5 wt% and then followed decreasing trend with further particle inclusion. Tensile and flexural modulus values of the particulate polyester composites significantly enhanced compared with the unfilled polyester composite. Spectrometry energy dispersion (EDS) results showed that the SSA contains elements and oxides may increase adhesion force with polymer.  In spite the particle content of SSA that used with polymer to produce various structures for different applications was low, however this study approved that using of SSA can protect the environment due to increasing the amount of SSA can affect the environment badly in addition to produce cheaper polymer composite for industrial applications.

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