DIYALA JOURNAL OF ENGINEERING SCIENCES

The goal behind this research is to highlight on structural system using composite steel plate shear wall, this approach is widely used in many countries, due to its desired features. Composite steel plate shear wall are often considered essential in design of building to resist seismic action. This paper discuss the effect of concrete strength on behavior of CSPW, for this objective one story one bay model with different compressive strength (25, 28 , 45, 50, 55, 65)MPa ,this model formed by finite element code which is advanced by university of Amirkabir. The accuracy of the representation of the model by numerical analysis, numerical result contrast with valid experiment which explain suitable agreement. Result show increasing the compressive strength would advance the cycle behavior. By contrast the result in elastic region, it was seen initial stiffness is not enhance by varying the compressive strength.

High Strength Concrete (HSC) is one of the most popular types of concrete used in the world. This type of concrete has a low rapid hydration of cementation materials with low w/cm and the external surrounding environment condition exposed the HSC to high autogenous shrinkage. If this shrinkage is not treated well that well led to cracking, in this case HSC need to convenient curing necessary at the earliest time. This study presents the use of Super Absorbent Polymer (SAP) as internal curing agent to eliminate shrinkage. Two types of shrinkage are tested in this study (Autogenous shrinkage and drying shrinkage).
Two groups of concrete mixes(A and B) are studied in this study each group have five types of concrete mixes, four mixes with high and ultra-high compressive strength (RPC, MRPC, HSC and SCC) and the last one with normal compressive strength (NSC). Group A represent concrete mixes without SAP addition and group B for concrete mixes with SAP. SAP was added for all mixes at 0.3% by weight of cement and adding 20ml water for each gram of SAP, specimens with dimensions (40*40*160) mm were used for testing shrinkage for each mix with and without SAP, average values for two specimens was taken as a results. It was found that concrete mixes of group B have lower shrinkage than the shrinkage of concrete mixes in group A at 28 days age with reduction of autogenous shrinkage(AS) of (57%, 35%, 37%, 44.5% and 37.5%) respectively and for drying shrinkage the percentage of reduction was (89.5%, 72%, 82%, 70% and 71%) respectively, addition of SAP to concrete mixes proves to have active effect in reducing the shrinkage of concrete.

This paper aims at investigating the behavior of cantilever beam in reinforced concrete frame modified by steel fibers. The study depends on adding steel fibers at the joint of beam column section to improves the ductility of the beam – column joint. Steel fibers of ratio (0.5%) and (1%) steel fibers by volume added for two specimens comparing with two others cast without steel fibers joint in R.C. frame. The cantilever frame behavior at applied load will be discussed in this study. The load applied to the frame at the edge of cantilever arms. The test results showed that the difference between the monolithic frame is larger in ultimate loads compared with non-monolithic, and the frame with 1% steel fibers have large load capacity compared with 0.5% steel fibers frame. The frame which cast monolithically shows highest resistance among the three other frames in ultimate load and flexural deformation, after load was applied to the four specimens the behavior of the frame up to the failure occurred in the beam-column joint at exterior face of the cantilever. beside studying the effect of steel fibers percentage and behavior of beam column joint, this study focuses also on investigating the difference between monolithic and non-monolithic concrete elements.

To make Power Plants (PPs) economical, the maintenance functions should be optimized by carefully selecting and planning the Maintenance Management System (MMS) that will address the maintenance needs of the plant at the least cost. This research was carried out to obtain a clear understanding of the Traditional method and to assess their suitability to selection the management system of maintenance in power plants in Iraq. The objective of the study was to select the most suitable MMS for Maintenance of Electric Power Plants (MEPP) to make the plants operate economically. The traditional method called Weighting Property Index (WPI) used for selecting MMS for MEPP. This method, which is based on weighting property method (WPM) uses a digital logic (DL) due to, makes the result more accurate because it eliminates the problem of the criteria have least important. The research showed, when applied the method (WPI), the results was indicate that the preventive maintenance, is one of the types of planned maintenance, and is the best strategy for MMS in implementation the works (MEPP) in Iraq, where was arranging the alternatives generally according to results which was obtained from the method (WPI) as follows; preventive maintenance is (6.67), predictive maintenance is (6.07), proactive maintenance is (5.89), run to failure is (5.5), and unplanned failure is (5.33). For further research can be used operational KPIs with maintenance KPIs and use of another alternative is design out maintenance with other alternatives.

Study of heat transfer augmentation with hybrid nanofluid represents a new class of heat transfer augmentation. The CFD model by using commercial software depending on finite volume technique and adopting SIMPLE algorithm is performed. Mixture of Aluminum Nitride (AlN) and alumina (Al2O3) nanoparticles into water as a basefluid is classified as a new class of hybrid nanofluids that can augment heat transfer. The nanofluid volume fraction and Reynolds number are in the range of (1% to 4%) and (5000 to 17000) respectively. The size diameter of nanoparticles and heat flux around a horizontal straight tube are fixed at 30 nm and 5000 w/m2 respectively. The numerical solution has been successfully validated by using an experimental data available in the literature. Results show that combination of AlN - Al2O3 nanoparticles into water basefluid tends to augment significant heat transfer performance.

Many models were introduced to estimate the roundabout entry capacity from 1980s until now. In the United States, transportation agencies adopted three different models from 1994 until 2010. The Austroads, the UK, and the HCM 2010 methods. In this paper, these three methods were used to analyze the field traffic data of Al-Quds roundabout, located near Baqubah City, simultaneously by utilizing a system dynamics model. The collected data included turning movements, circulating flows, and field calculated entry capacities whenever possible during the observation period which lasted for 14 consecutive hours. A comparison is then conducted on the resulting entry capacities and their variation over time. The results showed that the calculated capacity according to Austroads method is the highest at all times while the UK method was always a little lower and the HCM 2010 method was always the least on all entries. The UK method capacity estimates were the closest to the field measured capacities for they returned the least RMSE on all entries. Field capacities showed some tendency towards the Austroads results in the north and south bound entries which carry about 66% of the total traffic. While, field capacities showed more proximity towards the HCM capacity results in the east and the west bound entries which carry 34% of the total traffic.

In this study, the effect of low velocity impact response of Kevlar/carbon hybrid composite has been investigated. Then the impacted specimens were subjected to compression and buckling tests at room temperature experimentally. The height, width and thickness of the specimens are 150, 100 and 2.1 mm, respectively. Impact tests have been performed under different impact energy levels by using low velocity impact testing machine. Compression and buckling tests were conducted by Shimadzu testing machine. According to obtained results, the damage increases by increasing the impact energy level in the subjected specimens to impact test. Compression strength value is higher about 3 times than buckling strength value.

a field experiment was conducted at the soil research department station (Agricultural Research Office), located in Abu Ghraib district (20 kilometers west of Baghdad) during the spring season for year (2016) to study the effect of irrigation water quality of furrow irrigation system on chemical and physical properties of the Soil.
The field study carried out by using three types of saline irrigation water: (tap water) with (0.6 ds/m), two wells water with (3.0 ds/m) and (5.1 ds/m), and the alternating irrigation method through the continuation of irrigation to the end of the agricultural season using one irrigate of tap water followed by one irrigate of water well with (5.1 ds/m). The results showed increasing of EC_S and SAR values if salinity water used as (〖S_2> S〗_3 〖> S〗_1), respectively for the depths (20-30, and 30-45cm) more than the depths (0-10, and 10-20 cm) and decreasing of EC_S and SAR values at the depths (0-10, 10-20, and 20-30 cm) when the tap water (〖 S〗_0) is used. Also, increasing of the physical properties of the soil when the irrigation used by tap water (S_0), and, decreasing of the physical properties of the soil when the irrigation used by water salinity (〖S_2> S〗_3 〖> S〗_1), respectively, at the depth (15-30) more than the depth (0-15 cm).

Composite shell structures have many applications in aerospace industry in which deal with various loading abundantly. In present paper Strain gauge instrument with rectangular rosette strain gauges were used to detect the maximum stress and strain distributions along the shell composite structure. Also a finite element analysis was done for validation of experimental results. The FEM software used was ANSYS14. Impact test, density measurement, and bending test were performed in order to detect physical and mechanical properties such as toughness, principal stresses, and density, of the three laminated composite shells. In addition, the results between experimental and ANSYS were compared. It was observed that an important discrepancy is found between theoretical and experimental results. It was also found a large difference in modulus of elasticity, toughness, and tensile strength for each composite material. These differences are tabulated in many tables in the last paper.

Hemrin dam is an important dam in Iraq located on Diyala river which is considered as main tributary of Tigris. The sedimentation is very difficult problem and is considered the major problem affecting the utilization of the dam. HEC-HMS 4.1 software was used to made a simulation for sedimentation in Hemrin reservoir in order to estimate the amount of sediment entering and deposition in the reservoir for the period (1981-2014). The calibration processes were performed using field measurement data for flow of water from Diyala river, the result obtained from simulation process found that the average annual sediment discharge load to Hemrin reservoir is ( 3.43x〖10〗^6 Ton), while the average annual sediment deposited is (3.25x〖10〗^6 Ton).

In the present work the effect of Ingate Area on the Mechanical properties (σmax, σyield, E and hardness, stiffness) of as cast Al-4%Cu alloy had been studied, molds were made by sand casting with different ingate area (1cm×1cm, 1.2cm×1.2cm, 1.4cm×1.4cm, 1.6cm×1.6cm, 1.8cm×1.8cm, 2cm×2cm, 2.2cm×2.2cm, 2.4cm×2.4cm and 2.6cm×2.6cm). The process was done in normal condition (T=25Cᵒ, dry sand, constant speed, constant pour distance), while the casts prepared for the testing as a work piece to get the results. Also, Artificial Neural Network (ANN) had been adopted to predict the values of outputs (mechanical properties) and getting the mathematical equations that describe the relations between input and outputs parameters. From the results of the proposed work it conclude that mechanical properties magnitudes had been increased due to increasing in ingate area cast, and the relations between the ingate area and mechanical properties) had been detected depending on the results that gotten from ANN.

The turbulent lean premixed combustion simulation is implemented in 4- stroke spark ignition (SI) engine. The Turbulent Flame speed Closure model (TFC) is used in different turbulent flow conditions. The model is tested for a variety of flame configurations such as turbulent flame speed, the heat release from the combustion and turbulent kinetic energy in the radial direction of the cylinder at 15.5 mm below the top dead center TDC point. The simulation performs in the three cases of the (intake / exhaust) valve timing. The exhaust valve case is an essential leverage on the turbulent flame specification. The combustion period is very important factor in SI engine which is controlled especially by the turbulent flame speed. The turbulent flame speed and heat transfer is ascendant less than 10 % and 3% in case of intake and exhaust valves are closed respectively. Moreover, the results show that the brake power enhances less than 4% and more than 40% with increase fuel temperature 60 K and engine speed 3000 rpm respectively.