ISSN: 1999-8716

Volume 6, Issue 4

Volume 6, Issue 4, Autumn 2013, Page 1-119


EXPERIMENTAL FATIGUE STUDY of 6061 – T651 Aluminum ALLOY UNDER ALTERNATING ROTATING BENDING LOADING

Basim Hussein Abbas

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 6, Issue 4, Pages 1-13

Fatigue under constant and variable cyclic stresses of 6061 – T651 aluminum alloy was studied at room temperature using pure bending as a loading test. An empirical model was derived from the experimental data of surface crack lengths for short and long fatigue cracks and the corresponding number of cycles. Variable cyclic stresses test was carried out using three specimens of the same material. The proposed model was applied to estimate the life of specimens and it showed that good results can be predicted (under – estimate the life of the specimens), and gave good indication for warning before failure happens. From this study it was concluded that there is no need to establish the S-N curve of the material.

SETTLEMENT-TIME BEHAVIOR OF STEEL PILES IN GYPSIFEREOUS SAND - A MODEL PROTOTYPE STUDY

Waad Abdulsattar Zakaria

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 6, Issue 4, Pages 1-14

There are a lot of studies conducted on gypseous soils dealing with the effect of collapsibility on the general behavior of the soil concerning its strength properties, settlement indexes, volume-mass relationship and permeability. To get rid of the bad soil properties then one goes into another subject as dealing with the aspects of soil improvement or replacement and the like. This study is devoted to settlement investigation of a small prototype pile erected into gypsifereous soil, loaded to 70% of its ultimate bearing load, socked for two hours and then leached with water for seven days. In preparing testing soil, well graded sand is mixed with pure gypsum in ratios of gypsum content of 10, 20, 30, 50, 70%. The loading frame is locally manufactured as to apply loads and to record settlement of pile. The results revealed that when gypsum is less than 10% or 20%, settlement recorded is small. The settlement-time curves show a convetional “S” shape in a semi-log scale. Maximum settlement obtained is for gypsum content of 70% and is about 30% of pile diameter. Finally, three additional socking and leaching tests are also conducted by using 5% concentration of CH3COOH (acid), grade-60 viscosity oil, and kerosene for specimens containing 50% of gypsum. Specimen socked and leached by oil shows very little settlement, while the specimen treated with kerosene shows less settlement as compared with water. The
specimen treated with 5% concentration of CH3COOH shows 50% increase in settlement.

STUDY THE EFFECT OF HEAT TREATMENT TO MECHANICAL PROPERTIES FOR ALLOW ALLOY CASTING STEEL

Hatem Abd Hassan

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 6, Issue 4, Pages 14-23

In this research the degree of starting the end of transformation for phases have been identified in different averages levels of heating and cooling and calculated the transformation time in each case by using device of Dilatometer for casting steel DIN 1.2067. The behaviors of fatigue strength, tension strength, impact strength and hardness strength have been studied for four selection groups one of them casting and other three have been heated treatment such as quenching in water, quenching in water and tempering at 260 oC, quenching in water and tempering at 620 oC. These tests carried out by affecting of constant stress capacity for standard samples have cylindrical shape by using the rotating bending with stress ratio is (R= -1) and standard samples for testing tension strength and impact strength. The results have been shown that the heat treatments lead to improve fatigue strength, fracture stress, yield point, impact strength, hardness and the best was quenching in water and tempering at 260 oC.

FINITE ELEMENT ANALYSIS OF REINFORCED CONCRETE SLABS WITH SPHERICAL VOIDS

Amer M. Ibrahim; Nazar K. Ali; Wissam D. Salman

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 6, Issue 4, Pages 15-37

This paper presents a numerical analysis using ANSYS finite element program to simulate the reinforced concrete slabs with spherical voids when subjected to five point load. Six slabs with length 1.0m, width 1.0m, height (0.1m and 0.125m) and simply supported were modeled. Nonlinear materials behavior, as it relates to steel reinforcing bars and plain concrete, and linear behavior for steel plate is simulated using appropriate constitutive models. The results showed that the general behavior of the finite element models represented by the load-deflection curves at mid-span, ultimate load, load-maximum concrete compressive strain curve, and crack patterns show good agreement with the test data from the experimental test. The finite element models represented by this work can be used to carry out parametric study for the BubbleDeck slab specimens.

ASSESSMENT THE ORGANIZATIONAL STRUCTURE OF CONSTRUCTION COMPANIES USING TOPSIS TECHNIQUE

Hafeth I. Naji; Ali L. Abass

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 6, Issue 4, Pages 24-44

The subject of the decision-making in construction projects occupies the main concern in implementing most of the companies in developed countries, so there was significant interest in the development of methods for multi-criteria decision-making. And so as this research which focuses on the provision of Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) to assess the organizational structures in construction companies. Where some implementing companies could face to financial losses or a decline in expected profits during the implementation due to weaknesses in the organizational structure or not adopting the best organizational structure which able to provide the necessary data and information that will help the various administrative levels in the follow-up and control of project performance. This research aims to highlight the importance of organizational structure in the construction companies working at the University of Diyala, and how technology can be employed basis (TOPSIS) to assess the organizational structures in these companies through determining the used criteria to select the best company in terms of organizational structure. For the purpose of achieving the objective of research, it has been collecting its own data from the literature that dealt with the Technique for Order Performance by Similarity to Ideal Solution and organizational structures, and finally personal interviews of specialists from companies managers and directors of departments and project managers. The results of data analysis for the sample showed that the criteria overlap career, development of managers and employees and strengthen the ties between them, understanding the project and its objectives and to accelerate the process of decision-making, the memory of a strong institution are the most important criteria to make bilateral comparisons between companies, and the standard overlap career, understanding the project and its objectives and accelerate the process of decision- making are more important than the rest of the criteria in the evaluation of companies. Finally, and by calculating the relative closeness and index category of order companies find that Al Fao General Contracting Company has won the largest share of importance in comparison with other companies. Finally, there was a set of conclusions and recommendations of the various aspects of the topic from, accelerate the application of techniques of multi-criteria decision-making in the evaluation of projects in addition to expediting the application of organizational structures proposed by researchers to help companies managers to have efficient decision-making, which will lead to a process of setting and more effective control on the construction project.

FORECASTING OF EVAPORATION FROM HEMREN RESERVOIR BY USING ARTIFICIAL NEURAL NETWORK

SAAD SH. SAMMEN

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 6, Issue 4, Pages 38-53

The evaporation is one of the basic components of the hydrologic cycle and is essential for studies such as water balance, irrigation system design, and water resource management and it is requires knowledge of the values of many climatic variables. In order to estimate the evaporation, direct measurement methods or physical and empirical models can be used. Using direct methods require installing meteorological stations and instruments for measuring evaporation. Installing such instruments in various areas requires specific facilities and cost which is hard to be employed. Accordingly, this paper is an attempt to assess the potential and usefulness of ANN based modeling for evaporation prediction from Hemren reservoir by using daily temperature, relative humidity, wind velocity, sunshine hours, and evaporation data in Hemren meteorological station. Also, this study outlines a procedure to evaluate the effects of input variables on the output variable using the weight connections of ANN models.
The Lev. Marqn. Back Prog. (LMBP) has been utilized to construct the ANN models. For the development ANN model, different networks with different numbers of neurons and layers were evaluated. Mean Squared Error (MSE) and the Correlation Coefficient (R2) were employed to evaluate the accuracy of the proposed model. The study shows that the best model for estimation of evaporation is ANN (4-10-1), it have MSE equal to 0.112711 and the correlation coefficient (R2) equal to 0.999540.

USING A SOLUTION BASED ON PERLITE SAND PLASTER DECORATION OF BUILDINGS AND STRUCTURES

Zagorodnjuk L. H; Lesovik V. S; Mahmoud Shakarna

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 6, Issue 4, Pages 45-57

The nature of Arab society to focus on building on the houses and villas that offer privacy and comfort and luxury, and the high number of family members per requires a lot of people living in the homes of separate or villas. These houses should be built from materials which have the international standards in this area. One of the most important of these specifications are dry mixes.
The research aims to indicate the most important features dry mixes (perlite mixtures) which are used at present significantly whitening buildings and structures, and to indicate the most important specifications and requirements that must be met by these mixtures, as well as additives that are used to increase their effectiveness.
There were reached by the results of scientific experiments that we got a dry mixtures using world-class pearlite and basically meet the requirements of European specifications that determine heat recommendation of the type T1_1. 0 W / (m. K), and the type of T2_2. 0 W / (m. K) where we proved scientific experiments.

DESIGN AND SIMULATION OF PARALLEL CDMA SYSTEM BASED ON 3D-HADAMARD TRANSFORM

Ali T. Shaheen

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 6, Issue 4, Pages 54-69

Future wireless systems aim to provide higher transmission data rates, improved spectral efficiency and greater capacity. In this paper a spectral efficient two dimensional (2-D) parallel code division multiple access (CDMA) system is proposed for generating and transmitting (2-D CDMA) symbols through 2-D Inter-Symbol Interference (ISI) channel to increase the transmission speed. The 3D-Hadamard matrix is used to generate the 2-D spreading codes required to spread the two-dimensional data for each user row wise and column wise. The quadrature amplitude modulation (QAM) is used as a data mapping technique due to the increased spectral efficiency offered. The new structure simulated using MATLAB and a comparison of performance for serial one-dimensional (1-D) CDMA and parallel (2-D) CDMA is made under Additive White Gaussian Noise (AWGN), flat fading and multi-path selective fading channels conditions. It is found that 2-D CDMA has better speed and performance than serial 1-D CDMA.

EVALUATION OF LOCAL VOIDAGE IN TWO PHASE SYSTEM BY OPTICAL METHOD

Ali Z. Asker

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 6, Issue 4, Pages 70-80

One of the important characteristics in predicting the flow of two phases (gas and liquid) in the industrial equipment is the gas percentage in the liquid, which is called voidage. This characteristic can be measured by different methods; the optical method is one of them. In the present work, a He-Ne laser light is employed to measure the voidage. The measurement depends on the principle of laser light attenuation during its passage through a mixture of fluids, which is governed by Beer-Lambert law. The attenuated light is measured using silicon type detector and an oscilloscope with a plotter. The gas phase was air while the liquid phase was contaminated water situated in a vertical column. The experiments were done with different air flow rates in water (1, 2, 3, 4,5and 6 liters per minute) with two spot sizes of laser (5mm dia & 10 mm dia). The results illustrated the possibility of measuring the voidage using laser beam and are compared with another one based on the liquid level variation (level ratio) in the column. Furthermore, the results provide that the 10mm dia spot size of laser beam gives better results.

PROCESSABILITY AND DETERMINATION OF SOME MECHANICAL AND THERMAL PROSPERITIES OF FILLED AND UNFILLED POLYPROPYLENE / POLYAMIDE 6 BLEND

Najat J. Saleh; Jwan W. Mohammed

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 6, Issue 4, Pages 81-99

A new type of Bentonite filled PP/PA6 and red Kaolin filled PP/PA6 blends has been developed. It is Polypropylene and Polyamide 6 at constant ratio (80/20) and different weight fraction (0, 5, 10, and 15) % of both local Bentonite and Red Kaolin fillers were added respectively. Filled polymer blends were developed on a single screw extruder. Hardness, compression impact strength, and thermal stability of BN/PP/PA6 and RK /PP/PA6 blend system were determined at different temperatures, and different weight fraction of filler. The results shown hardness and compression increase while impact strength decrease with increase in weight fraction content. Also the results shown that thermal stability increases with increased weight fraction of filler. Bentonite filler produces better mechanical properties, than Red Kaolin fillers. Empirical equations are proposed and show a best fit with experimental data. Relevant contour diagrams, based on the proposed equations, for optimization of properties were also presented.

THE EFFECT OF SPIN COATING SPEED AND DEPOSITION PARAMETERS ON THE CRYSTALLINE SIZE OF ZnO THIN FILMS

Aqeel Ali Al-Attar; Safaa Mohammad Hasony; Ali Hussein Ali

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 6, Issue 4, Pages 100-106

ZnO thin films have been deposited onto the glass-substrates by the sol-gel spin coating method at different chuck rotation rates. This method was used for the preparation of thin films on the important semiconductors ІІ-VІ. The effect of deposition parameters on the structural, optical and electrical properties of the ZnO thin film was investigated. Zinc acetate dehydrate, 2- methoxethanol and monoethanolamine (MEA) were used as a starting material, solvent and stabilizer, respectively. XRD of the dried gel showed that weight loss continued until 300°C, with smallest particle size at 400 rpm spin coating speed.

DESIGN AND SIMULATION OF SELF TUNING CONTROLLER FOR DC SERVO MOTOR

Mustafa A. Khamis

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 6, Issue 4, Pages 107-119

This paper presents an adaptive controller which improves the tracking performance between the plant and the desired response to obtain model following (the plant response completely follow the desired response). The DC servo motor is used (with fixed and variable load) as the plant response for the adaptive controller and the type of the controller that designed in this paper is indirect self-tuning controller STC with the parameters estimation. The parameters estimation is obtained by using the Least Square Estimation method and the model following is achieved by pole placement design method. Matlab program is used to design and simulation the controller and the simulation results show that the tracking error is reduced until becomes zero. At this point the DC servomotor response is closed to the desired response by the proposed controller as applied to the dc servomotor, also when the gain or the load of the DC servo motor is changed the output response of the STC is closed to the desired response after some time due to the estimation process, and the best value of the forgetting factor is less than one.