Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : mechanical properties


Fine Aggregate Ratios Effect on Mechanical and Physical Properties of Pervious Concrete

Muyasser Mohammed Jomaa; Mohammed Sabah Irhayyim

Engineering and Technology Journal, 2016, Volume 34, Issue 9, Pages 246-260

The porous concrete applications and the process of production in different ways depending on the replacement of fine or coarse aggregate components of research important topics, The study dealt with production pervious concrete by depending on normal concrete by removing fine aggregate by four percentage by weight (25%, 50%, 75%, 100%), as was the work of trail mixtures of concrete for a reference mix of were depended mixture the weight [1:1.5:3] with a ratio (W/C) is equal to (0.40), which recorded the highest compressive strength of age (7) days, by the results tests show that the increased rate of removal of fine aggregate contributed to reduce the strength and density with the increase in porosity and permeability and absorption, as less density obtained is (1756.2)kg/m3 remove the fine aggregate by (100%), which gives less strength to compressive (14.28)MPa and the highest value for porosity (24.81%), as were better strength to compressive, splitting tensile, and bending are (36.77MPa, 4.28MPa, 4.4MPa), respectively to the proportion of removing fine aggregate (25%) compared to the reference mixture.

Comparative Study of Some Properties of Two Groups’ Binary Polymer Blends Prepared By a Twin-Screw Extruder

Sihama I. Al-Shalchy; Kadhum M. Shabeeb; Rula F. Hasan

Engineering and Technology Journal, 2015, Volume 33, Issue 8, Pages 1971-1985

In this paper, the preparation and compare of some mechanical and physical properties of two groups of polymer blends consisting of polyvinyl chloride with polypropylene (PP-PVC) and poly-vinyl chloride with high-density polyethylene (HDPE-PVC). Using a twin-screw extruder, three weight percentages of PP and HDPE (5, 10 and 15%) were used to prepare the polymer blends. Experimental investigation was carried out for analyzing the mechanical properties liketensile strength, flexural strength, compression, impact, and hardnessand physical properties (thermal characteristics and melt flow index) for the polymer blend samples. The results show that the polymer blend (HDPE-PVC) get higher values than polymer blend (PP-PVC) in fracture strength, young´s modulus, elongation, flexural strength, creep resistantand maximum shear stress and thermal characteristics, whereas the polymer blends (PP-PVC) get higher values in impact strength, fracture toughness, hardnessand compression and melt flow index. Besides, the increment in PP or HDPE content weak the properties of the polymer blends and the samples with (5%PP:95%PVC) and (5%HDPE:95%PVC)were the best among the other polymer blends samples.

The Influence of Quenching Media and Aging Time on Microstructure and Mechanical Behavior of 6061 Aluminum Alloy

Naser Korde Zedin

Engineering and Technology Journal, 2015, Volume 33, Issue 8, Pages 1757-1770

Aluminum-magnesium-silicon (Al-Mg-Si) alloys are medium strength, excellent formability, good corrosion resistance and widely used in extruded products and automotive body materials. The influence of quenching media with different aging time on microstructure and mechanical properties of 6061 aluminum alloy was investigated. The results show formation of (Mg2Si) and (CuAl2) phaseswhensolution treatmentwas applied (at 520°C for 2h,followed by quenching in water and oil at room temperature then aging (at 175°C for 2, 4and6h)) which resultimprovingof both the strength, hardness and decreases elongation. It can be noted that, the grains of samples which are quenching in water is finer than the structure of samples which are quenching in oil. The values of yield stress and ultimate tensile strength decrease respectively with increasing aging time to 6h as (258MPa) and (264MPa) for water quenching and (199MPa) and (235MPa) for oil quenching. In this piper were measured and discussedthe variation of the yield stress, ultimate tensile strength and elongation with different solution quenching and aging time.

Nano-SiO2 Addition Effect on Flexural Stress and Hardness of EP/MWCNT

E.A.Al-Ajaj; A.Sh. Alguraby; M.K. Jawad

Engineering and Technology Journal, 2015, Volume 33, Issue 7, Pages 1248-1257

Nano-SiO2 with different weight percentage (1,2 ,3, 4 and 5) % wt. , and 3% MWCNT were usedto fabricate nano-SiO2/MWNT/epoxy composite samples by hand layup method. Ultrasonic mixing processwas used to disperse the nano additives into the resin system. scanning electron microscopy (SEM)where usedto carry out the characteristic of fracture surface. By both the high aspect ratio and the very high modulus ofnano fillers. The mechanical properties of the composite with different weight percentages of nano-SiO2 havebeen investigated and After examine, the Scanning Electron Microscopy (SEM) explains well dispersednanotubes and SiO2 nano particles in the matrix. No evidence of agglomeration of the nanotubes can be foundin this micrographs. By adding SiO2 nano particles to epoxy/MWCNT composite, this would dramaticallyimprove the bending properties and The Young’s modulus has been doubled and quadrupled for compositeswith respectively 2 and 4 wt.% nano SiO2, compared to the pure resin matrix samples (3.36 ,4.06 ,and 1.59 )GPa respectively .While flexural strength has been increased in random manner with maximum value for 2 wt%(111 MPa). The hardness of nano composite increased with increase of SiO2 filler loading, it can be seen thatthe SiO2 filler greatly increased the hardness, which can be attributed to the higher hardness and moreuniform dispersion of SiO2 filler. The higher hardness is exhibited by the 5 wt% SiO2 filled compared to othernanocomposites. The results show that at 5wt% nano SiO2 content there is 11% increase in hardness

The Effect of Rolling and Heat Treatment on Mechanical Behavior of 6061 Aluminum Alloy

Ruaaabd al Kaream Salman

Engineering and Technology Journal, 2015, Volume 33, Issue 6, Pages 1389-1398

In this study, the influence of bothheat treatment and cold working (rolling) on the tensile properties andhardness of6061 aluminum alloy sheets was investigated. The solution heat treatment is first performed at about 520°C 1 hr followed by rolling to(40% and 60%). Artificial aging is obtained by heating to about 180 °C for 1/2hr and 2 hr.Theexperimental work has revealed that when two strengthening mechanism(cold work and aging)are combined, the values of the mechanical properties are come up.Increasing the aging time from ½ hrto 2hr with redaction in area was causing increase in the values of the strength and hardness and dropping the elongation. In the other hand, increasing the redaction in area from (40%) to (60%) with aging was rising the value of the strength and hardness and dropping the elongation. The changes in mechanical properties were discussed as a result of increasing the dislocation density(result of rolling) and formation of precipitation(effect of aging) which are interface with the motion of dislocation and causes hindering of dislocation.

Study the Effect of Surface and Internal Heat Treatment on Mechanical Properties of C40 Steel Alloy

lamyaa kalel; Ahlam Abd Alamer Al khafaji; Sabah N. Mahmood

Engineering and Technology Journal, 2014, Volume 32, Issue 4, Pages 922-931

The research aims to study the effect of quenching, tempering and laser surface treatment on the mechanical properties of C40 steel. The steel specimens were heated to a temperature of 860°C, soaked for 60 minutes and quenched in oil and then tempered at different temperatures (100,200,300,400,500,600,700) °C.
Laser hardening were carried out by using Nd: YAG laser with different pulses up to 5 pulses, the applied laser energy was 500 mJ.
The mechanical tests such as: impact test and microhardness, were carried out for the specimens before and after heat treatment. Microstructure evaluation was carried out using computerized optical microscope. The results showed an improvement in the internal and surface properties of the metal.

A modeling comparison studies for thermo-mechanical and other Properties of RHDPE and RLDPE Wastes

Falak O. Abas; Raghad U.Abass; Mohammed O.Abass

Engineering and Technology Journal, 2014, Volume 32, Issue 3, Pages 681-701

A recycled waste plastic (recycled high density poly ethylene RHDPE and recycled low density poly ethylene RLDPE) are exposed to environmental conditions during the usage for many years ago. Also the chemical contaminants in the internal composition had effects on the thermo-mechanical and other properties for these wastes.
Then weathering effect data are examine for both locally and international wastes on their thermo-mechanical and chemical properties such as (Tensile strength, modulus, elongation, impact and permeability) respectively.
Afterward different mathematical software models are applied to analysis these weathering – properties data in order to estimate the more effective properties that changed by these weathering conditions such as (concentration of contaminant, time, temperature, thickness of specimen, length of spectra, basic property).
The results shows that a multi-polynomial model has a best fit for most or several of properties to active weathering variables, also gave a vary residual and deviation than experimental analyzed data for both sources of wastes local and international RHDPE and RLDPE. Also results of thermo-mechanical and chemical properties prove that both tensile strength and modulus of elasticity thermo-mechanical properties and permeability / length of spectra chemical property were given a high quality of correction and fitting factor from 93-99 %, with less deviation and residual function was produced. And analyzed weathering properties of RHDPE gave a best fit than RLDPE; all of them fitted the mathematical software model below:

…(1)

Where:
a, b, c …J = coefficient of the best fit model.
x1 = concentration of contaminants.
x2 = time of aging.

Mechanical, Thermal and Wear Characteristics of Polymer Composite Material Reinforced with Calcium Carbonate Powder

Aseel B. Al-Zubaidi; Ahmed A. Al-Tabbakh; HanaaA. Al-Qaessy; Ragad N. Al-Kaseey

Engineering and Technology Journal, 2014, Volume 32, Issue 3, Pages 519-532

Quick mast–105 is a well-known epoxy-based adhesive used in fabric reinforcement, bonding of wooden parts and variety of metals. Its mechanical and thermal properties are still limiting factors for extended technological and industrial applications. Enhancement of mechanical, wear and thermal characteristics of this epoxy resin using a cheap filler of CaCO3powder is the focus of the present study. The mechanical properties are demonstrated in terms of the flexural modulus, hardness and impact strength of the reinforced cured compound while thermal properties are presented through thermo gravimetric analysis and thermal conductivity coefficient. Results show that addition of 15% by weight of CaCO3 to the epoxy resin improves the mechanical properties and the thermal resistance of the end product paving the way for wider applications in industry and technology. Wear characteristics show that the reinforced product is suitable for high-speed applications.

Effect of Particle Size on the Physical and Mechanical Properties of Nano HA/HDPE Bio-Composite for Synthetic Bone Substitute

Jenan Sattar Kashan; Jafar.T.Al-Haidary; Amin D.Thamir

Engineering and Technology Journal, 2014, Volume 32, Issue 2, Pages 286-297

The effect of using nano particle size of Hydroxyabatite to produce HA/HDPE biocomposite
by Hot Pressing technique was studied by investigating the effect of particle
size and production technique on the physical and mechanical properties of the biocomposite
at different volume fraction of nano HA powder and different compression
pressures.
Nano particle size and Hot Compression technique had great impact on the properties
by reversing the behavior of the bio composite comparing with that using micro scale
particle size in some of previous studies .The fracture strength and hardness increased
with increasing the filler content by more than 200% for strength and 300-400% for
micro hardness values , the densities increased with increasing filler content
compressing pressure where as the porosity decreased.
The modification in mechanical properties due to filler particle size and production
process enhanced the osteo- conductivity of biomaterial to use in different bone substitute
applications.

Study Fatigue Behavior of Friction Stir Welded Joints for Dissimilar Aluminum Alloys (2024 -T3 and 7020 -T6)

Muna K. Abbass; Ali H. Ataiwi; Ahmed Ameed

Engineering and Technology Journal, 2014, Volume 32, Issue 2, Pages 439-452

The aim of the present work is to investigate the fatigue behavior of friction stir welded joints for dissimilar aluminum alloys (2024 -T3 and 7020-T6). Friction stir welding (FSW) had been done for 6.6 mm thick plate by using NC milling machine with R18 tool steel of 18mm with shoulder diameter and 6mm pin diameter with different tool designs; threaded cone with double bevel, threaded cylinder with concave shoulder of 4°, and beveled cone with concave shoulder of 4°. FSW were carried out under various welding parameters, travel speed of 40, 50, 75 mm/min, rotation speed range (275-1250) rpm and tilt angle of (Ɵ = 3°) with counterclockwise revolution.
Many non- destructive inspections and mechanical tests were performed to evaluate welded joints to determine the best welding parameters. Fatigue test has been done at constant stress amplitude cantilever with stress ratio of (R= -1). The results showed that maximum tensile strength and joint efficiency were 360MPa and 86% respectively for dissimilar joints which were welded at 40mm/min travel speed and 550 rpm rotation speed by using threaded cone with double bevels.

To Study the Effect of Fillers on the Glass Fiber Reinforced Composites

Rafah A.Nasif

Engineering and Technology Journal, 2014, Volume 32, Issue 1, Pages 47-53

This study was carried out to investigated the effect of ceramic fillers (aluminum oxide Al2O3 and titania TiO2 ) and industrial wastes (red mud and copper slag) with weight fraction (10% wt)on the mechanical properties of composite material consist of epoxy reinforced with glass fiber with weight fraction (40/50)%wt .Some tests are carried out like: impact strength, tensile strength and harness and results have been compared with composite material reinforced only with glass fiber (50/50)%wt . The results show that the composite reinforced with TiO2 had higher value of impact strength and lowest value of tensile strength compared with other composites, while composite material reinforced only with glass fiber had higher value of tensile strength. Also, it can be seen that all hybrid composites have hardness values higher than that of composite material reinforced only with glass fiber and the highest hardness value was for the composites material reinforced with Al2O3.

Influence of Ceramic Particles Reinforcement on some Mechanical Properties of AA 6061 Aluminium Alloy

Jameel Habeeb Ghazi

Engineering and Technology Journal, 2013, Volume 31, Issue 14, Pages 2611-2618

This paper is to investigate the influence of adding 5,10 and 15 weight percentage
silicon carbide particles on some mechanical properties of 6061 Aluminium alloy.
The composites Al6061/SiC were prepared by stir casting technique.
The results revealed that as the reinforcement content was increased, there were
significant increases in the ultimate tensile strength, yield strength and hardness of
composites accompanied by a reduction in its percentage of elongation.
Microstructural studies have been carried out to understand the nature of structure.

Mechanical Properties of Reactive Powder Concrete (RPC) with Various Steel Fiber and Silica Fume Contents

Lubna S. Danha; Wasan Ismail Khalil; Hisham M. Al-Hassani

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3090-3108

An experimental work was carried out to investigate some mechanical properties
of Reactive Powder Concrete (RPC) which are particularly required as input data for
structural design. These properties include compressive strength, tensile strength
(direct, splitting and flexural), flexural toughness, load-deflection capacity and static
modulus of elasticity. The effects of three variable parameters on these properties were
carefully studied which are, the silica fume content SF (0%, 10%, 15%, 20%, 25%, and
30%) as a partial replacement by weight of cement, hooked macro steel fibers volume
fraction Vf (0%, 1%, 2% and 3%) and superplasticizertype(Sikament®-163N and
PC200).The diameter of the steel fiber is 0.5mm and its length is 30mm with aspect
ratio 60.The experimental results showed that as the silica fume content (SF) increases
from 0% to 30% the compressive strength significantly increases, while the increase in
tensile strength is relatively lower. The inclusion of steel fibers leads to a considerable
increase intensile strength, while the addition of steel fibers causes a slight increase in
compressive strength of RPC as fiber volume fraction increases from 0% to 3%.The
increase in the steel fibers volume fraction and silica fume content improved the loaddeflection
behavior and consequently gave higher ductility and fracture toughness of
RPC.

A Comparison Study of Mechanical Properties between Friction StirWelding and TIG Welded Joints of Aluminum Alloy (Al 6061-T6)

Muna Khethier Abbass; Hassan Hady Abd

Engineering and Technology Journal, 2013, Volume 31, Issue 14, Pages 2701-2715

In this study two different welding processes have been considered, a
conventional tungsten inert gas (TIG) and a relatively new solid state welding
known as friction stir welding (FSW). TIG welding process has been performed on
Al 6061-T6 of thickness 4mm by using filler metal of Al-Mg alloy type (ER5356)
according to AWS classification metal with tungsten electrode (EWth-2) and arc
voltage of (12V). Various welding currents of (125, 160, 200, 225) Amp were used
under argon as shielding gas of flow rate of (15-20 cf / hour) and welding speed of
280 mm/min.
Friction stir welding is carried out using automatic milling machine with five
different welding or bed speeds of (25-50-80-100-125 mm/min) and five different
tool rotation speeds of (630-800-1000-1250-1600 rpm). Tool steel of type R18
consists of a shoulder with diameter of (20 mm) and pin of diameter (5.5 mm). Xray
radiographic inspection, tensile test and microhardness test of FSW and TIG
joints at optimum welding conditions were made.
The results indicate that the best tensile strength of FSW joints is 289 MPa and
joint efficiency is 79% which were welded with welding parameters of (1250 rpm,
800 rpm and 50 mm/min, 125 mm/min) respectively. While in case of TIG joint the
best tensile strength is 210 MPa and joint efficiency is 57%.
It was found that the microhardness hardness values in the TIG welded joints
are lower than that of the FSW joints. The formation of fine equiaxed grains and
very fine strengthening precipitates (Mg₂Si) in the stir or weld region are the
reasons for higher tensile strength and hardness of FSW joints compared to TIG
joints.

Study the Effect of Glass Fibers on Mechanical Properties of Epoxy Composites

Raghad Hussein Mohammed

Engineering and Technology Journal, 2013, Volume 31, Issue 5, Pages 653-659

The tensile behavior, flexural strength and impact strength were studied in this research for some epoxy composites. First, epoxy composite reinforced with carbon fibers (chopped), secondly,hybrid epoxy composite reinforced with carbon fibers (chopped) and glass fibers (woven roven) with volumefraction(30) % for each type.The tests were done at room temperature (34±2 ºC). In this work the hybrid composite (C+G/Epoxy) have the higher mechanical properties than that composite (C/Epoxy).The results shown that the exists of woven glass fiber increasing the tensile behavior, flexural strength and impact strength of hybrid composite in comparison with the composite reinforced with randomly chopped carbon fibers.

Mechanical Properties of Tempered Nanobainite Steel

Dhafir S. Al-Fattal; Najmuldeen Y. Mahmood

Engineering and Technology Journal, 2013, Volume 31, Issue 1, Pages 107-119

The mechanical properties of 62 SiMnCr 4 steel transformed isothermally at 280ºC for 5-hours were investigated. The hardness of nanobainite steel was equivalent to tempered martensite steel. The hardness decreases significantly at high tempering temperatures in excess of 500ºC. Yield strength of about 2GPa and ultimate tensile strength of 2.3GPa have been achieved for nanobainite steel. Furthermore, the high strength is frequently accompanied by relatively good percentage elongation of 8.25%. The strength decreases and the ductility increases with increasing tempering temperature. Nanobainite steel has a high charpy impact energy of 170 J which decreases linearly with increasing tempering temperature. Fatigue strength of nanobainite steel is higher than tempered martensite, its decreases with increasing tempering temperature.

Study the Effect of Volume Fraction of Mica With Different Particle Size on the Mechanical and Electrical Properties for Unsaturated Polyester Composites

Rafah A.Nasif

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3573-3580

This study was carried out to investigate the effect of adding mica (5, 10, 15, 20, 25
% vf) with variable particle size (35, 57, 70μm) on the mechanical and electrical
properties of the unsaturated polyester composites. Some mechanical tests were carried
out like (impact strength, flexural strength) and dielectric strength. Flexural strength
and dielectric strength were found to increase with filler concentrations whereas impact
strength was found to decrease at higher concentrations for all particle size.

Mechanical Properties and Dynamic Response of Lightweight Reinforced Concrete Beam

AzizI brahimAbdulla; a A. Ali; Alya; Ahmed Adnan Ghanee

Engineering and Technology Journal, 2012, Volume 30, Issue 2, Pages 293-311

The study is conducted to perform two goals: The first geal is to produce a
lightweight concrete using major components which are locally available with
some standard admixtures.Many mixtures are prepared using many ratios of
superplasticizer (SP) and silica fume (SF) admixtures to yield a lightweight
aggregate concrete, the effects of using different ratios of these admixtures on unit
weight, compressive strength and flexural strength are studied individually and
accumulatively. The secondis to study the dynamic specifications of normal and
lightweight reinforced concrete beams.
The results showed that the increasing in dosage of superplasticizer (SP) for
(LWAC) increases the density of (LWAC), and the increasing in dosage of silica
fume (SF) decreases the density of (LWAC). The experimental impact tests for
R.C. beams shows that the lightweight R.C. beams have a better response under
impact loading with respect to the maximum dynamic deflection (2.955mm for
normal weight beam and 1.58mm for lightweight beam). Also,Impact force
transferred to supports reactions of lightweight beams is smaller within 45% than
the impact force transferred to reaction of normal weight concrete under the same
impact load, and the time to reach 90% damping equal to 1.223 sec and 1.6 sec for
lightweight and normalweight R.C. beams respectively. Also, the reinforced
concrete beams are tested under repeated impact load up to failure. The tests
showed that the no. of blows to cause first crack for lightweight concrete beams
more than twice of this for normalweight concrete beams.

Effects of Lamination Layers on the Mechanical Properties for Above Knee Prosthetic Socket

J. S. Chiad; S. S. Hasan; M. J. jweeg

Engineering and Technology Journal, 2009, Volume 27, Issue 4, Pages 759-775

In order to initiate a database on materials properties of typical lamination
used in above knee prosthetic limb socket fourteen group of different lamination
materials layers are manufactured using perlon and fiber glass and acrylic resin
.The effect of increasing and decreasing of perlon and fiber glass layers on
mechanical and physical properties are examined subjected the eighty two
manufacturing sample of the different fourteen group of lamination to tensile and
flexural test .
Results show that the lamination which was layup from three layers of perlon plus
two layers of fiber glass plus three layers of perlon gives the optimum mechanical
properties . Comparing this lamination with the standard lamination used in
Baghdad center of five layers of perlon plus two layers of fiber glass plus five
layers of perlon it can be seen that ,in spite of the big reduction in perlon layers
form ten to six layers the yield stress increased with 14.75% while ultimate
strength remains at the same value and bending stress decreased with 1.3% only . It
is recommend to use this type of lamination for the layup the above knee socket
because it meets the requirement of good socket design for acceptable mechanical
properties and its minimizing the cost of socket lamination to suitable cost value.
Also it was found that increasing the fiber glass layers from zero to two layers
with fixing perlon layers leaded to increased in( E y ult s ,s , , flex flex s ,E ) with
(40%,30.4%,110.5% 36.4%and 20.4%) respectively. At the same time the results
show that the lamination group of sandwich lay up during which the layers of
perlon distributed equally (homogeneously) on each side of the central fiber glass
layers improved the mechanical properties set ( E y ult s ,s , , flex flex s ,E ) with ((21-
59)%,(12.4-66.4)%,(46.6-150)%,(5.2-60.2)%,(27.5-44.8)%) respectively compared
with the others group of unequally distributed lamination .

Predicting Mechanical Properties of High Performance Concrete by Using Non-destructive Tests

Sura F. Al-Khafaji; Waleed A. Al-Qaisi; Shakir A. Al-Mishhadani

Engineering and Technology Journal, 2009, Volume 27, Issue 3, Pages 425-444

In this study, high performance concrete mixes were produced by using high
range water reducing agent and also by using 10% silica fume or 10% high
reactivity metakaolin as a partial replacement by weight of cement. Three cement
contents (350, 450, and 550) kg/m3 were used through this study. A total of 330
(100 mm) cubes, 132 (100×200 mm) cylinders, 132 (100×100×400 mm) prisms,
and 66 (150×300 mm) cylinders were casted and cured to the required age of test .
All specimens were cured in tap water except 165 cubes, which were submerged in
Cl ˉ + SO4ˉ ˉ solution at concentration identical to those present in severe
aggressive environment to study the effect of this solution on the compressive
strength of high performance concrete mixes. Compressive strength, splitting
tensile strength, modulus of rupture, static modulus, rebound number, ultrasonic
pulse velocity, dynamic modulus, initial surface absorption, density ,and total
absorption tests were investigated for all mixes at 7, 28, 90, and 120 days age.
Results of the destructive tests (compressive tensile strength, strength, splitting
modulus of rupture, and static modulus) and non–destructive tests (hammer,
ultrasonic pulse velocity, and dynamic modulus) are statistically analyzed by using
SPSS Ver.15 software to study the possibility of predicting the mechanical
properties of high performance concrete by using non–destructive tests. Simple and
multiple linear regression analysis of the obtained results leads to the proposed
statistical models for evaluating the compressive strength, splitting tensile
strength, modulus of rupture, and static modulus by using one or two or three of
the above mentioned non–destructive tests. Analysis of variance (ANOVA)
and t–test was also used to investigate the adequacy of the statistical models.