Journal of Engineering

It is commonly known that Euler-Bernoulli’s thin beam theorem is not applicable whenever a
nonlinear distribution of strain/stress occurs, such as in deep beams, or the stress distribution is
discontinuous. In order to design the members experiencing such distorted stress regions, the
Strut-and-Tie Model (STM) could be utilized. In this paper, experimental investigation of STM
technique for three identical small-scale deep beams was conducted. The beams were simply
supported and loaded statically with a concentrated load at the mid span of the beams. These
deep beams had two symmetrical openings near the application point of loading. Both the deep
beam, where the stress distribution cannot be assumed linear, and the existence of the openings,
which causes stress discontinuity, make the use of Euler-Bernoulli’s thin beam theorem not
applicable. An idealized STM for the beam was first established and then experimental test was
carried out to study the capability of STM to deal with the distortion of stress caused by the
presence of near-load openings in addition to the nonlinear distribution of stress occurring in
deep beam. The test results showed that the beam designed using STM was able to withstand a
load higher than the designed ultimate load. The service load, in the other hand, was within the
range of the estimated one. The outcome of this study can then be added to the relatively few
available experimental studies related to STM technique to enhance the validation of STM to
efficiently treat different structural configurations where the linear stress assumption cannot be
applied.

The execution phase of the project is most dangerous and the most drain on the resources
during project life cycle, therefore, its need to monitor and control by specialists to exceeded
obstructions and achieve the project goals. The study aims to detect the actual reasons behind
mismanagement of the execution phase. The study begins with theoretical part, where it deals
with the concepts of project, project selection, project management, and project processes. Field
part consists of three techniques: 1- brainstorming, 2- open interviews with experts and 3-
designed questionnaire (with 49 reason. These reasons result from brainstorming and
interviewing with experts.), in order to find the real reasons behind mismanagement of the
execution phase. The most important reasons which are negatively impact on management of the
execution phase that proven by the study were (Inability of company to meet project
requirements because it's specialized and / or large project, Multiple sources of decision and
overlap in powers, Inadequate planning, Inaccurate estimation of cost, Delayed cash flows by
owners, Poor performance of project manager, inefficient decision making process, and the
Negative impact of people in the project area). Finally, submitting a set of recommendations
which will contribute to overcome the obstructions of successful management of the execution
phase.

Building Information Modeling (BIM) is becoming a great known established collaboration
process in Architecture, Engineering, and Construction (AEC) industry. In various cases in
many countries, potential benefits and competitive advantages have been reported. However,
despite the potentials and benefits of BIM technologies, it is not applied in the construction
sector in Iraq just like many other countries of the world.
The purpose of this research is to understand the uses and benefits of BIM for construction
projects in Iraq. This purpose has been done by establishing a framework to application of BIM
and identifying the benefits of this technology that would convince stakeholders for adopting
BIM in the construction sector in Iraq.
Through this research, the use of this technology has been clarified by using the proposed
framework (application Revit software and linking it with the MS Project and Navisworks
Manage software on the case study) to identify the important benefits to be the beginning to
apply the Building Information Modeling technology in the construction sector in Iraq.
The research results indicated that such proposed framework can greatly improve the
performance of the current state of project management through improving the project quality,
cost saving and time-saving.

Gypseous soils are widely distributed and especially in Iraq where arid area of hot climatic is
present. These soils are considered as problematic soils; therefore this work attends to improve
the geotechnical properties of such soil and reduce the dangers of collapse due to wetting
process. In this research, undisturbed soil sample of 30 % gypsum content from Karbala city is
used. The Single Oedometer collapse test is used in order to investigate the collapse
characteristics of natural soil and after treatment with 3%, 6%, 9%, 12% and 15% of Cutback
Asphalt. Moreover, two selected additive percentages (9% and 12%) are used to evaluate the
suitability of using the Cutback Asphalt for improvement of the bearing capacity of gypseous
soils. A steel model box is used for this purpose, the treatment depth is equal to one and twice
the footing width. The tests results showed that the total settlement of 25 mm of treated soil with
(MC-30) material can be achieved at vertical stress lower than that value required for natural
soil. Also, thickness of treated layer with (MC-30) material below the proposed foundation has a
significant effect on the value of bearing capacity of the soil. The rate of salt dissolved (C.V) is
extremely decreased especially at all percentages of Cutback Asphalt. The best bearing
improvement ratio is found at 9% asphalt and at a depth equal to foundation width. However, the
Cutback Asphalt can be successfully used by 12% for collapse potential treatment while it is not
suitable for improvement of the bearing capacity of gypseous soils.

Electro-chemical Machining is significant process to remove metal with using anodic
dissolution. Electro-chemical machining use to removed metal workpiece from (7025)
aluminum alloy using Potassium chloride (KCl) solution .The tool used was made from copper.
In this present the optimize processes input parameter use are ( current, gap and electrolyte
concentration) and surface roughness (Ra) as output. The experiments on electro-chemical
machining with use current (30, 50, 70)A, gap (1.00, 1.25, 1.50) mm and electrolyte
concentration (100, 200, 300) (g/L). The method (ANOVA) was used to limited the large
influence factors affected on surface roughness and found the current was the large influence
factors with (72.17%) . The results of the optimization of comparison of experimental and
prediction conditions current at level-1(30 A), gap at level-1 (1.00mm ) and electrolyte
concentration at level-1(100(g/L)) shown the average experiments and prediction surface
roughness (1.352 μm) and (1.399 μm) respectively.

The present investigation aims to study the effect of heat treatment by quenching in different
quenching media (salt water, water and oil) following by tempering on wear resistance of EN25
steel. EN25 steel is an alloy of medium carbon low alloy steel which is used for many applications
requiring high tensile strength and wear resistance such as connecting rods, adapters and in power
sectors extensively. The specimens are machined to 20 mm in length and 10 mm in diameter. This
study is done by two stages: The first stage is done by austenitizing EN25 steel to 850℃ for 1 hr
by quenching the specimens in three different quenching media and then tempered at 300℃ in air.
While the second stage is performed by wear test. Dry sliding wear test is done by using pin –on
disc technique by varying the loads as 5, 10, 15, 20 and 25 N, also varying the time as 5, 10, 15,
20, 25 and 30 min respectively. The microstructure examination, hardness and followed roughness
tests are also done for the specimens before and after wear test. The results of this work showed
that an improving in wear resistance and hardness for the specimen quenched by salt water more
than for water and oil. At the same time the roughness decreasing for the specimen quenched by
salt water more than for water and oil.

In this investigation, metal matrix composites (MMCs) were manufactured by using powder
technology. Aluminum 6061 is reinforced with two different ceramics particles (SiC and B4C) with
different volume fractions as (3, 6, 9 and 12 wt. %). The most important applications of particulate
reinforcement of aluminum matrix are: Pistons, Connecting rods etc. The specimens were prepared
by using aluminum powder with 150 µm in particle size and SiC, B4C powder with 200 µm in
particle size. The chosen powders were mixed by using planetary mixing setup at 250 rpm for
4hr.with zinc stearate as an activator material in steel ball milling. After mixing process the powders
were compacted by hydraulic unidirectional press type (Leybold Harris No. 36110) at 250 Kg/cm2
according to (ASTM-D 618). Finally the green compacts were sintered at 500 ℃ for 3 hr. by using
electrical furnace with argon atmosphere. There are many examinations and tests were done for the
produced metal matrix composites (MMCS), (Al/ SiC and Al/B4C) such as examination of the
microstructure, mechanical tests (hardness and compressive strength), physical tests (density test
before and after sintering, also porosity test). The results of this investigation showed that improving
the physical properties (theoretical density, experimental density, porosity) and mechanical
properties (Rockwell hardness and compressive strength).

The bit record is a part from the daily drilling report which is contain information about the
type and the number of the bit that is used to drill the well, also contain data about the used
weight on bit WOB ,revolution per minute RPM , rate of penetration ROP, pump pressure
,footage drilled and bit dull grade. Generally we can say that the bit record is a rich brief about
the bit life in the hole. The main purpose of this research is to select the suitable bit to drill the
next oil wells because the right bit selection avoid us more than one problems, on the other hand,
the wrong bit selection cause more than one problem. Many methods are related to bit selection,
this research is familiar with four of those methods, which they are: specific energy method, bit
dullness way, cost per foot method, offset well bit record and geological information way. Five
oil wells have been studied in Rumaila Oil Field in South of Iraq which they are R-531, R-548,
R-536, R-544 and R-525. The wells R-531, R-536 and R-525 are vertical wells; the wells R-548
and R-544 are directional wells at angle of inclination 8.79◦ and 16.62◦ respectively.

The present work is concerned with the investigation of the behavior and ultimate capacity of
axially loaded reinforced concrete columns in presence of transverse openings under axial load plus
uniaxial bending. The experimental program includes testing of twenty reinforced concrete columns
(150 × 150 × 700 mm) under concentric and eccentric load. Parameters considered include opening
size, load eccentricity and influence of the direction of load eccentricity with respect to the
longitudinal axis of the opening. Experimental results are discussed based on load – lateral mid
height deflection curves, load – longitudinal shortening behavior, ultimate load and failure modes. It
is found that when the direction of load eccentricity is parallel to the longitudinal axis of openings,
column behavior is more pronounced when than the direction is normal to the longitudinal axis of
openings.

Based on a finite element analysis using Matlab coding, eigenvalue problem has been
formulated and solved for the buckling analysis of non-prismatic columns. Different numbers of
elements per column length have been used to assess the rate of convergence for the model. Then
the proposed model has been used to determine the critical buckling load factor ( ) for the
idealized supported columns based on the comparison of their buckling loads with the
corresponding hinge supported columns . Finally in this study the critical buckling factor ( )
under end force (P) increases by about 3.71% with the tapered ratio increment of 10% for
different end supported columns and the relationship between normalized critical load and
slenderness ratio was generalized.

This research aims to study the effect of microwave furnace heat on the mechanical properties
and fatigue life of aluminum alloy (AA 2024-T3). Four conditions were used inside microwave
furnace (specimens subjected to heat as dry for 30 and 60min. and specimens subjected to heat as
wet (water) for 30 and 60 min.), and compared all results with original alloy (AA 2024-T3).
Tensile, fatigue, hardness and surface roughness tests were used in this investigation. It is found
that hardness of dry conditions is higher than wet conditions and it increases with increasing of
time duration inside microwave furnace for dry and wet conditions. Also, tensile strength has the
same behavior of hardness, but it increases with decreasing of time. Dry condition for 60 min.
shows the higher fatigue strength than other conditions. Surface roughness parameter (Ra) of dry
conditions is higher than wet conditions and it decreases with increasing of duration of time.