Issue 1

Emperical and Numerical Solution Of Seepage Problems Underneath Hydraulic Structures

Rafid Alboresha; Uday Hatem

Anbar Journal for Engineering Sciences, 2021, Volume 12, Issue 1, Pages 1-9
DOI: 10.37649/aengs.2021.171193

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 seep-age 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 ac-count 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

Progressive Collapse Analyses of Buildings Subjected to Earthquake Loads

Dr. Fareed H. Mosawi; Dr. Haider S. Al Jubair; Mr. Hussein A. Ahmed

Anbar Journal for Engineering Sciences, 2021, Volume 12, Issue 1, Pages 10-19
DOI: 10.37649/aengs.2021.171194

Progressive collapse is a partial or total failure of a building that mostly occurs when the build-ing 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. Three-dimensional nonlinear dynamic analyses are carried out using SAP2000 V.20 program. The ef-fects 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.Keywords:Progressive collapse, Concrete buildings, Seismic load, Nonlinear dynamic analysis, Plastic hinge.© 2014

Numerical Investigations of Bond-Slip Performance in Pull-Out High Strength Concrete Specimens Subjected to Elevated

Akram S. Mahmoud; Shamil K. Ahmed

Anbar Journal for Engineering Sciences, 2021, Volume 12, Issue 1, Pages 20-28
DOI: 10.37649/aengs.2021.171195

The concrete members several blessings over steel beam, like high resistance to prominent tem-perature, higher resistance to fatigue and buckling, high resistance to thermal shock, fire re-sistance, 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 rein-forcement of steel bar systems below static pull-out loading tests subjected to elevated tempera-tures. This numerical technique relies on relative slip and therefore the stress of bond distribu-tions 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

Influence of Various Types of Twisted Tape inserts on Hydrody-namic, Pressure Drop and Thermal Heat Performance in Heat Ex-changers: A Review Study

Ahmed Ramadhan Al-Obaidi; Hayder Mohammad Jaffal

Anbar Journal for Engineering Sciences, 2021, Volume 12, Issue 1, Pages 29-46
DOI: 10.37649/aengs.2021.171196

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 pub-lished in corrugated pipes with varying field applications to provide good information for engi-neers and designers whom dealing and concerning with improvement of heat performance in heat exchanger corrugated pipes.

Effect of Anchorage Length on the Shear Capacity of High Strength Concrete Deep Beams

Maytham Khalid Gatea a; Dr. David A.M.Jawad b

Anbar Journal for Engineering Sciences, 2021, Volume 12, Issue 1, Pages 47-56
DOI: 10.37649/aengs.2021.171197

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 con-trolled in the high compressive concrete deep beams due to bottom steel yielding. Finally, the ex-perimental test results are compared with predictions of the strut-and-tie method according to the ACI 318-14 and a good agreement was found.

Optimum performance of rotor blade with different airfoil for Primus Wind power AIR 40 Wind Turbine 12VDC

Hawraz .O. Tahaa; Iyd Eqqab .M. Al-Hamookab

Anbar Journal for Engineering Sciences, 2021, Volume 12, Issue 1, Pages 57-64
DOI: 10.37649/aengs.2021.171198

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 com-monly used among wind turbines is small axis wind turbine. Analysis to optimization power coef-ficient ( ) of a small wind turbine blade design model (Primus Wind power AIR 40 Wind Tur-bine 12VDC) are evaluated and discussed in this study. A shape of blade wind turbine is the pri-mery 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 coeffi-cient 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.

Numerical Investigation on heat transfer enhancement and entropy generation in a triangular ribbed-channel using nanofluid

Mohammad N. Dahham; M. A. Ahmed

Anbar Journal for Engineering Sciences, 2021, Volume 12, Issue 1, Pages 65-75
DOI: 10.37649/aengs.2021.171199

In this paper, turbulent convective heat transfer in a triangular-ribbed chan-nel has been numerically investigated. SiO2-water with nanoparticles volume fraction of 4% and nanoparticles diameters of 30 nm is employed with Reyn-olds number ranging from 2000 to 8000. The governing continuity, momen-tum 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 in-creasing of Reynolds number and rib height. In addition, the highest perfor-mance factor can be obtained at Reynolds number of 6500 and rib height of 1.5 mm.

Minimizing Evaporation Losses from Small Reservoirs (Wadi Houran-case study)

Rasha I. Naif a; Isam M. Abdulhameed

Anbar Journal for Engineering Sciences, 2021, Volume 12, Issue 1, Pages 76-82
DOI: 10.37649/aengs.2021.171200

minimizing the surface area of a reservoir during maximum evaporation losses period. A mathe-matical 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 re-duced 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.

Simulation of Storm Sewer Network Using a Storm Water Man-agement Model (SWMM), Ramadi City as a Case Study

Ethar I. Mohammad; Ayad S. Mustafa; Ammar Adham

Anbar Journal for Engineering Sciences, 2021, Volume 12, Issue 1, Pages 83-89
DOI: 10.37649/aengs.2021.171201

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 sew-er 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 develop-ment. 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.

A proposed plan for implementing the public transport policy in the city of Ramadi / Anbar University as a model

S. Thameel; Th. Mahmood; A. Mustafa; A. Mohson

Anbar Journal for Engineering Sciences, 2021, Volume 12, Issue 1, Pages 90-99
DOI: 10.37649/aengs.2021.171202

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.

Investigation of Clayey and Sandy Soil Characteristics Polluted with Crude Oil

N. Jajjawi; N. M. Salim; K.Y. Al-Soudany

Anbar Journal for Engineering Sciences, 2021, Volume 12, Issue 1, Pages 100-107
DOI: 10.37649/aengs.2021.171203

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

Free Vibration Analysis of Clamped Laminated Composite Plates with Centeral Crack

Khaldoon F. Brethee

Anbar Journal for Engineering Sciences, 2021, Volume 12, Issue 1, Pages 108-115
DOI: 10.37649/aengs.2021.171204

A finite element method for free vibration analysis of generally laminated composite plateswith central crack and clamped edges have been studied using ANSYS 5.4 program. The fiber-reinforced composite materials are ideal for structural applications where highstrength-to-weight and stiffness-to-weight ratios are required, where structures must safelywork 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-dimensionalfundamental frequency of vibration decreases with presence of cracks because, therigidity of cracked plate decreases. The natural frequency of plates depends on size andshape of the cracks, the effect of number of layers is found to be insignificant beyond fourlayers and the change of fiber orientation increasing the fundamental frequency of vibration.The results obtained have been compared with the available published literature with goodagreement results