Journal of Engineering and Sustainable Development (JEASD)

Experimental investigations had been done in this work to demonstrate the effect of graphite filler contents on the dynamic behavior of (30%) weight fraction glass-polyester sandwich panel under low velocity impact. The composite sandwich panels are manufactured using the honeycomb core and laminated composite face sheets. The wet hand layup technique is used. The mechanical properties were tested based on ASTM D-638. The panel is fixed from three sides and the other is free. The impact load is applied. The dynamic response of the plate is measured using vibration data collector (TVC 200). The panel is supported also on a rigid foundation. The steel impactor of 15 kg weight dropped from 2 m height. The deformation is measured using vernier caliper. The results showed that the mechanical properties are improved when the graphite filler content increased up to 7.5% and then decreased after that. The same dynamic behaviors were obtained but differ in magnitude. The minimum deflection and deformation takes at 7.5% filler content for both face and core. At 7.5% filler content the deflection and deformation decreased by 28% and 60% respectively less than the unfilled panel. The effects of using different faces with the same core have a little variation.

A new mathematical finite element model suitable for the general bending analysis of annular plate structure is developed in polar coordinates system depending on the strain based approach has been derived. The element is simple and contains only the essential degrees of freedom. The element has 15 degrees of freedom, three at each node and satisfies the exact representation of the rigid body modes of displacement. The results obtained by using the proposed element in several numerical problems have shown that a rapid convergence to exact solution can be obtained with acceptable degree of accuracy when only few element are used. The element has the advantage over the other available annular plate elements. The improvement obtained is due to the fact that all the displacement fields of the present element satisfy the exact representation of rigid body modes of displacements then the shape function error due to rigid body modes becomes zero. Also, the present element satisfies the full geometry of the annular plate due to this point discretization error becomes zero. Finally the error due to strain mode becomes very small because the present element satisfies the compatibility equations of strains and the 12th coefficients of strain mode derived exactly from partial differential equations of strains. The numerical solution of several problems by using the present element proved to be powerful in the structural bending analysis of circular annular plates. Its results are better than the solution of other elements and packages with respect to analytical.

Experimental and numerical investigations to study the effect number of blade on the rotating stall phenomenon and pressure fluctuations in centrifugal blower. The experimental test rig which concludes a centrifugal blower, pressure sensors and measurement instrumentations are design and constructed for the present work. A data acquisition system (hardware) and its software have been designed and manufactured to transfer the signal from pressure sensor to the computer and then analysis with time and frequency domain.The experimental study has been carried out by measuring the static pressure variation and pressure fluctuation for three cases of impeller which they different in number of blades (5, 9, 10) and outlet blade angle. Measuring of static values has been completed at various points prepared on the front-wall of the volute casing along one path for three cases of impeller. This path is angular path around the impeller.The experimental results demonstrate that the pressure fluctuations for various mass flow rates are a non-periodical nature and the pressure fluctuations amplitude increase as the mass flow rate decrease. The results indicate that the impeller with nine number of blades demonstrate high pressure fluctuation comparison with other case.Numerical simulation has been carried out on present centrifugal blower to analyze both flow field and pressure fluctuations by using FLUENT 14 package. The numerical simulation has been completed by solving the continuity and momentum equations with moving reference frame technique inside the blower.

The experimental work of this study includes testing sixteen reinforced concrete one-way slabs cast using high strength self-compacting concrete (HSSCC) with using steel fibers to evaluate their flexural behavior and strength. The slabs were subjected to concentrated transverse loads (loads were distributed across the entire width of the slab) at the third points. All tested slabs have dimensions of 1000×450×50 or 70 mm. The parameters considered are slab thickness, steel reinforcement ratio (ρ) and steel fiber volumetric ratio (Vf). The effect of these parameters on the behavior of the tested slabs included investigation of deflection, failure mode, and ultimate loads. Two different failure modes were predicted either flexural tension mode or flexural shear mode or a combination of these two.

Fiber reinforced concrete (FRC) may be defined as a composite materials made with Portland cement, aggregate, and incorporating discrete discontinuous fibers and silica fume. In this paper an attempt is made at 300°C to present the results of an experimental investigation carried out on (FRC). While Fiber content was used as (0%, 0.5% and1%) by weight of mix and silica fume was used as (0%, 5% and 10%) by weight of cement. Effect of the addition of silica fume and steel fiber on the various strengths of concrete was studied. The strengths considered for investigation are compressive strength and flexural strength. Cubes of size (150) mm for compressive strength; beams of size (100 mm x 100 mm x 500 mm) for flexural strength, were used as specimens. All the specimens were water cured for 28 days and tested subsequently. The compressive strength decreases by about (18%, 18.1% , 20% ) for (0% steel fiber) at 300°C with no silica fume, 5% and 10% silica fume respectively and the compressive strength decreases by about (16%, 20 % , 24% ) for (0.5% steel fiber) at 300°C with no silica fume, 5% and 10% silica fume respectively while the compressive strength decreases by about (15%, 15.5%, 16% ) for (1% steel fiber) at 300°C with no silica fume, 5% and 10% silica fume, respectively.

In this paper, a dynamic analysis of strip machine foundation is placed at the middle of the top surface of two-layer saturated sand with different states (i.e. loose, medium and dense), and vertical harmonic excitation is carried out with assessment of liquefaction potential and building up of the excess pore water pressure. The dynamic analysis is performed numerically by using finite element software, PLAXIS 2D. The soil is assumed as elastic perfectly plastic material obeys Mohr-Coulomb yield criterion. A harmonic load is applied at the foundation with amplitude of 25 kPa at a frequency of 5 Hz.A parametric study is carried out to evaluate the dependency of machine foundation on the modular ratio of soil layers. It was concluded that the displacement decreases remarkably when E1 (elastic modulus of the top soil layer) is duplicated 2-4 times E2 (elastic modulus of the underlying soil layer), then the effect decreases. The pore water pressure increases remarkably when E1 is increased to about 5 times E2, then the effect decreases. Liquefaction potential zone (when the effective stress approximately equals to zero) forms first near the end of the loading adjacency to the surface at shallow depth of the soil and extended to few meters for all frequencies.

This study aims to the design and manufacture of a split Hopkinson tension bar apparatus. The dynamic tensile behavior of hybrid composite materials at high strain rates is investigated. The most important characteristic of split Hopkinson apparatus is a (gun system) responsible of dynamic tension process depending on a spring system in its operation. Two groups of materials were tested at different strain rates; first group is woven fiber glass/ epoxy composite, woven carbon fiber/ epoxy composite and hybrid woven glass/ woven carbon epoxy laminates. The experimental results for the first group showed that the values of maximum stress, specific absorbed energy and kinetic energy increased approximately 12.4 %, 11% and 10% respectively for woven fiber glass/ epoxy composite when it’s hybridized with woven carbon fiber/ epoxy composite. In the second group using woven jute fiber as a natural material which have low cost and is environmental friendly, when these materials are hybridized with glass fibers and carbon fibers resulted in improves of the tensile properties. When woven jute fiber hybridized with glass fibers the value of maximum stress, absorbed energy and kinetic energy increase by approximately 38.33%, 38% and 55 % respectively. On the other hand hybridization of woven jute fibers with woven carbon fibers lead to increase in the values of maximum stress, absorbed energy and kinetic energy approximately 43%, 44% and 68% respectively. Based on experimental results the modulus of elasticity is increased with increasing the strain rates.

The soft Rake in multiple access systems such as interleave division multiple access (IDMA) is the most critical part in terms of the computational complexity. In this paper, the problem of choosing effective Rake paths in such systems among multi-path components is considered. The path selection problem is formulated as a problem with a convex objective function. A decision rule for choosing the proper path number of the soft Rake based multiuser combiner is derived. The decision rule is very simple and can get quite close to the optimal scheme that cannot be implemented in practice due to its complexity. Simulation results are presented to compare the system performance with the proposed path selection scheme and that of the conventional scheme.

Asphalt absorbed by aggregates; can be determined either using effective specific gravity or using Bulk Impregnated Specific Gravity(BISG) , the later has been used in this research. Four types of coarse aggregates, taken from four different quarries in Iraq, have been used. The aggregate types classified into crushed and uncrushed and sub classification according to the aggregate sizes had been done. The aim of this research is to find an empirical relationship between asphalt and water absorption by coarse aggregates brought from different source. To achieve this aim, sixty-two coarse aggregate samples were prepared and tested. In this research, three models were developed to predict asphalt absorption depending on water absorption values. Furthermore, High statistical correlation can be expected due to high acceptable estimated values of the coefficients of determination (R2) such as the values of (R2) s are 0.89, 0.87, and 0.76 to predict the amount of asphalt absorption by knowing its water absorption for general, crushed, and natural aggregates respectively. Finally, additional two models were developed to predict bulk impregnated specific gravity depending on the aggregate apparent and bulk specific gravities.

The proportional-integral-derivative (PID) controllers are the most popular controllers used in industry because of their remarkable effectiveness, simplicity of implementation and broad applicability. However, tuning of these controllers is time consuming, not easy and generally lead to poor performance especially with non-linear systems. This paper presents an artificial intelligence (AI) method of particle swarm optimization (PSO) algorithm for tuning the optimal (PID) controller parameters for steam engine speed control (SESC) system to achieve the mean objective which is the tracking between the reference speed and the output speed .This approach has superior features, including easy implementation, stable convergence characteristic and good computational efficiency over the conventional methods. The PID conventional controller had been applied and results were compared with the automatic tuning PSO-PID for (SESC) using Simulink of Matlab . Simulation results for the proposed method give optimum input/output tracking and the error equal zero without using the conventional solutions for standard engine control problems like cascade feedback gain and dither signal ,where in traditional tuning method of PID the tracking cannot achieve exactly without error, unless using conventional solutions.

This paper is concerned with the development of computational model of nonlinear response of hybrid reinforced concrete beams using finite element method with layering technique. The degenerating shell element with material nonlinearity is used to analyze the beams. The area of steel reinforcement is represented by an equivalent thickness. Perfect bond between the concrete and reinforcement has been assumed. The elasto- plastic behavior of the steel is used. Both multilinear and elastic-perfect plastic models have been adopted to represent high-strength and normal concrete’s stress-strain behavior, respectively. A comparison between the proposed model and experimental results that published by other researchers have shown a good agreement.

This study involves the design and construction of a split Hopkinson pressure bar apparatus as well as an investigation of the effects of high speed impact on two types of composite materials. A unique spring operated striker mechanism is designed and tested, thus introducing a major simplification to SHPB design requirements. Impact testing velocities of up to 25m/s are achieved. Samples results of impact tests on unidirectional glass fiber and unidirectional carbon epoxy are presented with a comparison between them. The effects of strain rate on specimen properties (compressive stress and strain) are determined. A strain rate range of 107-252 /s is achieved using impact speed range of 3.39-9.98 m/s for the unidirectional glass fiber composite. The corresponding ranges for the unidirectional carbon composites were 485-951/s strain rate and 6.68-13.28 m/s impact velocity. The results indicated that the max stress and strain are all increased with increasing the strain rate for both types. The carbon/epoxy showed higher properties compared with the glass/epoxy. The carbon samples sustained higher range of strain rate resulting in higher stresses and strains.

Many instruments and systems are available for engineering surveys. The total stations are capable of the measuring with a high degree of precision in a single instrument. Total stations device are used for station setting up, setting-out many points from one station.Their major purpose of this work is to take advantage of total station for setting up building and to establish 3D representation using AutoCAD program.The area of the study was Civil Engineering Department at Baghdad University campus AL Jadiriyah. The completion of the work is done in two stages;1.The field work: In this stage, the Total Station Nikon Nivo-5C was selected for the current study. This device was measured horizontal and vertical distance, elevations, and coordinates from a single set up. This data directly stored on memory.2.The office work: In this stage, AutoCAD program is adopted for design and establish 3D representation of the building to be completely faster and easier.Finally, AutoCAD models provided the basic building information such as boundaries, dimensions and positions. This method is used for construction surveys, designer works and other users.

Baghdad city after 2003 emergence of slums in many different areas of Baghdad, due to a variety of reasons, mainly lawlessness after 2003 and the weakness of control municipalities on the land of the state and the land uses, in addition to economic, housing, social, urban and poor in the laws and regulations planning and housing. Multiple laws were passed belong slums, but they cannot prevent these slums, because they need to treatment the reasons slums first, and then prevent it and find suitable solutions. There are different policies to treatment the slums in the world, and vary these policies as factors and the nature of its appearance, and from one country to another, and the most important policies is comprehensive or partial removal and find alternative, or policy development through the rehabilitation of area and supplying services. The research concluded that Al Qader, Al Shaab and New Baghdad municipalities are the most containment for the slums in Baghdad city, because it is located on the edge of the master plan of Baghdad city and the presence of unused urban spaces. The research recommended preparing a database of slum area and ordering them according to priority and including them in projects of housing, as well as moving away from ownership of slums for residents on the condition proper planning alternatives to solve the problem of slums and observance of human rights.

The surveying maps especially (cadastral maps and topographical maps) are considered the most important types of maps in cities, because its importance lies in the design, modernization and development of urban planning for the city because it contains all the elements and natural landmarks that found in the region, so the surveying map have great importance for Decision-maker, designers and researchers, scholars and all maps users.As a result of urban development, investment and construction in Iraq, emerged the need to produce digital maps instead of old paper maps that are still used in some government institutions as yet, so as to keep up with technical progress and the technological revolution taking place in most progressing countries of the world, the great development of the software and computer hardware removed a lot of obstacles in the production of maps which allowed the possibility of linking data and information with its geographical positions via coordinates, also allowed the possibilities of measurement , analysis and interpretation from aerial photographs and the information that sent from satellites ,and extraction the data and information to create maps, in order to save effort , time and money.Therefore, this research represent a method of producing satellite image with corrected coordinates and high-resolution for the purpose of preparation surveying map that contain all the terrain elements and ......