Anbar Journal of Engineering Sciences

A finite element method for free vibration analysis of generally laminated composite plates
with central crack and clamped edges have been studied using ANSYS 5.4 program. The fiber-reinforced composite materials are ideal for structural applications where high
strength-to-weight and stiffness-to-weight ratios are required, where structures must safely
work during its service life. But damages initiate a breakdown period on the structures.
Cracks are among the most encountered damage types in the structures. The non-dimensional fundamental frequency of vibration decreases with presence of cracks because, the
rigidity of cracked plate decreases. The natural frequency of plates depends on size and
shape of the cracks, the effect of number of layers is found to be insignificant beyond four
layers and the change of fiber orientation increasing the fundamental frequency of vibration.
The results obtained have been compared with the available published literature with good
agreement results.

The focusing in this study was on the contaminated-uncontaminated soils' properties which
studied by performing experimental tests included, Atterberg’s limit, specific gravity, compaction, unconfined compression, and direct shear tests. Different % of crude oil was used in the
contaminated soils which are performed by mixing the soils using different percent of were oil
of 3 %, 6 % and 9 % by dry weight. The main effect of oil contamination causes a reduction in the
liquid and plastic limit values for clayey soil. Besides oil contamination gives a reduction in the
maximum dry unit weight as well as a decreasing the optimum water content with comparison
to original soil (clayey and sandy soil). The angle of internal friction is decreased for sand while
it increases for clay is one of oil contamination results

The development of cities in the infrastructure and urbanization and the increase in the
population make people increase in the purchase of the private car, which in turn causes the
congestion , pollution , accident and noise especially after 2003, as Iraq's import of cars
increased to 5,800,000 cars distributed between the provinces, as 3Anbar province ranked
ninth in the development number of cars with 174,000 cars according to the Central Bureau of
Statistics of the Ministry of Planning. The university is the largest governmental institution that
has the largest traffic volume of vehicles. We have three directions for entering the Anbar
university they are east, middle and west directions. Total traffic volume from east, middle
and west direction is 2165 vehicles which lead to traffic congestion in Ramadi city and Anbar
university. The total traffic volume in private transportation in east, middle and west direction
is 727,515 and 923 vehicles respectively. No of students in private transportation in east,
middle and west direction is 4617, 3185 and3985 passengers respectively. As results of this
research, there are three proposed parks one of them in the Sujaria at east direction, second
park in Ramadi center at middle direction and third park in 5km area at west direction. In this
paper, we make comparing between private and public transport in terms of fuel costs and
time from the origin (the three proposed parks) to destination (Anbar University) assuming
that private cars stopped in those three parks by using Park & Ride System and used buses
with capacity of 40 passengers to transport students to the university. Depending on no. of
passengers in private transportation from the three proposed parks to university we got the
No. of buses from east park (Sujaria area), middle park (Ramadi center) and west park (7km
area) to university which were 28, 20 and 25 bus respectively because each bus can transport
four times

Ramadi city is suffering from severe flood problems during rainfall season as in many cities in
developed countries. Storm Water Management Model (SWMM) was used to simulate storm sewer network in the study area and depending on design rainfall intensity of 9.6 mm/hour. The
rainfall intensity was proposed to increased by two to three times of the design intensity because
of the absence of metrological stations in the study area to record rainfall intensity data of the
rain storm. The intensity increasing by three times led to maximizing the flood risk by 43%. The
proposed management to overcoming this problem is linking the collateral lines in Al-Andalus
and Alhoz suburbs by additional pipes, this method reduces the percentage of flooding to 31%.
Moreover, Economic Indicators (EI) were suggested to evaluate the cost of the network development. The area index (
) which represents the total cost of the added pipes to the total area of
the suburb, and the longitudinal index (
), which represents the total cost of the added pipes to
the length of the main pipe, the magnitudes of these indexes are 178 US dollar/hectare, and 57 US
dollar/m respectively

Current paper proposed a new technique to reduce evaporation from small dams reservoirs by
minimizing the surface area of a reservoir during maximum evaporation losses period. A mathematical relationship linking the depth of water with the surface area of the reservoir has been
formulated, and its integration can be used to estimate conservable water quantities. Reducing
the water level in the reservoir to the minimum permissible level before the dry months has reduced the evaporation losses by 65% and 51% for the two scenarios. These two scenarios have
been conducted by assuming that the dry months start with the presence of the water level in the
reservoir at a height of 14 and 12 m, respectively. On the other hand, evaporation losses during
drought months have been decreased by 24%. By this technique, it can be possible to obtain wide
areas suitable for agriculture, contributing to the economic and social development of the region.
Also, Depth index(DI) suggested in this study and defined as the ratio of volume of the water in
the reservoir to corresponding surface area, to compare the location of the best dam among the
13 proposed dams in Wadi Houran by reducing evaporation losses. The results of this index
showed the best location was at DI=10.901 in DM 7, and the worst is at DI=2.425 in DM 8.

In this paper, turbulent convective heat transfer in a triangular-ribbed channel has been numerically investigated. SiO2-water with nanoparticles volume
fraction of 4% and nanoparticles diameters of 30 nm is employed with Reynolds number ranging from 2000 to 8000. The governing continuity, momentum and energy equations in addition to low Reynolds number k-ε model
have been transformed into body-fitted coordinates system and then solved
using finite volume method. The effects of Reynolds number and rib heights
on Nusselt number, pressure drop, thermal-hydraulic performance factor and
entropy generation are presented and discussed. It is observed that the
Nusselt number, pressure drop and thermal performance increase with increasing of Reynolds number and rib height. In addition, the highest performance factor can be obtained at Reynolds number of 6500 and rib height of
1.5 mm

The increasing price of fossil derivatives, global warming and energy market instabilities are a
major problem. In recent years, these problems led to an increasing using of renewable energy
sources such as wind energy. Wind turbine used to extract this energy from the wind to produce
power or electricity. Due to low cost, easy for maintenance and it is, portability the most commonly used among wind turbines is small axis wind turbine. Analysis to optimization power coefficient ( ) of a small wind turbine blade design model (Primus Wind power AIR 40 Wind Turbine 12VDC) are evaluated and discussed in this study. A shape of blade wind turbine is the primery parapeter affected the power output of wind turbine. In this type of turbine NACA2411
used as the blade airfoil as represent shape of blade. For this goal, 185 different airfoils selected.
For this purpose, using the XFOIL software to simulate the properties of each airfoil at Re
(1.0*105, 1.5*105, 2.0*105, 2.5*105, 3.0*105 and 3.5*105) and angle of attack from 0˚ to 10˚, Then
elimination criteria was performed for removing those airfoils would not suitable for the purpose
up on their effiency. At the end of analysing Matlab software used for calculate the power coefficient and selecting the best airfoils design for used manufacture anew blade for that type of small
wind turbine with better power coefficient. The output of XFOIL and matlab software showed by
tabulates and graphs. As a results show 3 airfoils were selected due to their performance better
than other airfoils from an initial group of 185 as exemplification of the methodology namely
S1210,SD7034 and S2091, The maximum that has been achieved by which used airfoil
S1210 equal to 0.52 at Re 350000.

Ten simply supported deep beams with high strength concrete (C55 MPa) have been casted and
subjected to a four-point loading test. Different parameters were examined for their influence on
specimen behavior. These parameters were the shear span to overall depth ratio (a/h), the overall
depth of deep beams (h), and additional anchorage length beyond the centerline of support (la).
The experimental results show that the beam capacity decreases as the shear span to the overall
depth ratio increases, and the overall depth and embedment length decrease. The major effect of
anchorage length on the shear strength is studied. Different failure modes were observed which do
not match strut-and-tie failure modes. The shear compression and anchorage failures were controlled in the high compressive concrete deep beams due to bottom steel yielding. Finally, the experimental test results are compared with predictions of the strut-and-tie method according to the
ACI 318-14 and a good agreement was found

Numerous inserts types are employed in different heat transfer improvement application devices.
In this review study is forced on various types of twisted tape inserts in heat exchanger pipe.
Geometrical configurations of twisted tape for example twist direction; length, width, space, twist
ratio etc. were highly effect on flow pattern, hydrodynamic flow and heat transfer performance.
In this review study observed that using different types of twisted tapes can improve thermal
performance and hydrodynamic as compared to smooth pipe (without twisted tape). The review
investigations found that improvement of thermal performance happens owing to decrease in
pipe cross area, leads to rise in mixing flow, turbulence flow intensity flow and rise in swirl flow
established through different kinds of twisted tapes. This article dealt with investigations published in corrugated pipes with varying field applications to provide good information for engineers and designers whom dealing and concerning with improvement of heat performance in
heat exchanger corrugated pipes.

The concrete members several blessings over steel beam, like high resistance to prominent temperature, higher resistance to fatigue and buckling, high resistance to thermal shock, fire resistance, robust resistance against, and explosion. However there are some disadvantages as a
result of exploitation totally different materials to product it. The most downside of structural
concrete member is its deprived the strength to tensile stresses.
The bond mechanism between steel bars and concrete is thought to be influenced by multiple
parameters, like the strength of the encompassing media, the prevalence of cacophonous cracks
within the concrete and therefore the yield stress of the reinforcement. However, properties of
concrete mass has significantly effect when it was subjected to elevated temperature.
The objective of this paper presents the results that allocating with the bond behavior of the reinforcement of steel bar systems below static pull-out loading tests subjected to elevated temperatures. This numerical technique relies on relative slip and therefore the stress of bond distributions done the embedded length and size of the bar within the concrete cylinder specimens. The
obtained results square measure given and commented with the elemental characteristics of
ferroconcrete members. The comparison showed smart agreement with experimental results.

Progressive collapse is a partial or total failure of a building that mostly occurs when the building loses primary structural elements (typically columns) due to accidental or natural hazards.
The failure of structures due to an earthquake is one of the most important and frequent types of
progressive collapse. In this study, the finite element method is used to assess the response of
multistory reinforced concrete buildings subjected to column loss during an earthquake. Threedimensional nonlinear dynamic analyses are carried out using SAP2000 V.20 program. The effects of different parameters on the progressive collapse behavior are investigated, namely: the
location of the removed column within the ground floor; the method of column removal (sudden,
in two-steps, and in four-steps) and the removal timing during the earthquake. It is demonstrated
that the collapse occurs when all or most of the hinges at the bases of the ground floor columns
reach their collapse level. The chosen column removal timing and policy affect the structural
behavior considerably. It is realized that, the risk of building collapse increases when the removal
timing harmonizes with the peak ground acceleration timing. Based on the adopted earthquake
characteristics and building configurations, it is found that, the two steps removal scenario is the
most dangerous one.

Hydraulic structures are structures submerged or partially submerged in water, they’re used to
retain or divert natural water flow. Any hydraulic structure that retains water is faced with seepage problems as the water seeks the path with the least resistance through or under the hydraulic
structure. If the water carries materials as it flows or exerts high pressure on the floor of the
structure, it will cause failures such as piping and cracks and there are many ways to prevent
that, including cutoffs. In this paper, seepage is analyzed for different cases by using the empirical
method (Khosla’s theory) and the numerical method by using computer software (SEEP/W). The
results had some slight differences between the two methods as a result of not taking into account the effect of soil characteristics of the empirical method. However, the water pressure
heads underneath the impervious floor that calculated by the numerical method were greater.