Print ISSN: 1814-6120

Online ISSN: 2311-8385

Volume 12, Issue 2

Volume 12, Issue 2, Autumn 2012, Page 1-119


Optimum Design of Open Reinforced Concrete Circular Cylindrical Tanks Rest on Ground

Nabeel A. Jasim; Jaffar A. Kadim

Basrah Journal for Engineering Science, Volume 12, Issue 2, Pages 1-13

A computer program has been generated to calculate the optimum dimensions and the amount of
reinforcements for open reinforced concrete circular cylindrical tanks rest on ground. The design is based on
limit state method for both ultimate and serviceability limit states in accordance with the British Standards B.S.
8110 and B.S. 5337. The cost of concrete, steel, and formwork are considered. The procedure is based on the
interior penalty method to find the optimum solution for the non-linear programming problem. The tank consists
of cylindrical wall and circular base and the joint between them was considered as partially fixed. The design
variables consist of tank geometric variables in addition to steel content in seven positions. The effect of the
design capacity of the tank, bearing capacity of the soil, unit price of steel and concrete, and finally unit cost of
formwork was studied. It is found that the reduction of the bearing capacity of the soil linearly increases the cost
of the tank. The increase of concrete and steel unit costs leads to increasing the tank height while the increase of
formwork unit cost enhances the tank diameter, to reach the optimal design.

Analysis of Ferrocement Slabs Using Finite Element Method

Ihsan Qasim Mohamad

Basrah Journal for Engineering Science, Volume 12, Issue 2, Pages 14-19

This paper is concerned with the application of finite element techniques to the nonlinear analysis
of ferrocement slabs. Both material and geometric nonlinearities are considered in the analysis.
Concrete compression is modelled by a plasticity model and smeared cracking approach is used for
tensile cracking. Degenerated thick shell elements employing a layered discretization through the
element are adopted. Analyzing of a ferrocement slab does validation of the proposed model.

Forced Convective Heat Transfer for a Rotating Horizontal Cylinders in a Laminar Cross Flow

Ahmed K. M. Alshara

Basrah Journal for Engineering Science, Volume 12, Issue 2, Pages 20-34

This study investigates the effect of rotating two rows of horizontal cylinders on forced convection heat transfer in cross flow. Each row consists a three rotating horizontal cylinders heated at constant temperature. The governing equations for the steady, laminar, two dimensional, incompressible flow and constant fluid properties are solved numerically using the finite element method with FlexPDE soft package for a two rows of rotating cylinders at the same direction and at opposite directions. The main parameters are: Reynolds number (4010Re−=), Prandtl number (7.0Pr=), dimensionless longitudinal pitch (SL=1.5-2.5), dimensionless transverse pitch (ST=1.5-2.5) and the dimensionless angular velocity (Ω=0-3) (for both directions clockwise CW and counter clockwise CCW). It is found that the average Nusselt number increased with increasing Re and ST, and decreases with Ω and SL. The results are compared with other authors and give a agreement.

Design and Implementation of a Computerized Balancing System

Jaafar Kh. Ali; Saleh I. Najem

Basrah Journal for Engineering Science, Volume 12, Issue 2, Pages 35-47

In this work, a new computerized measurement system for multi-plane flexible rotor
balancing has been designed and implemented. This system can be used to modernize and
enhance conventional low-speed balancing machines or for field balancing applications. This
system adds very important features to balancing machines such as multi-plane flexible rotor
balancing, high accuracy, stability, and high dynamic range. Also, the proposed flexible rotor
balancing technique permits accurate balancing of high-speed rotors utilizing low-speed
balancing machines or field balancing at speeds lower than the critical speeds. The proposed
digital Wattmetric technique in conjugation with advanced measurement circuitry have led to
significant improvement in balancing accuracy even when the unbalance signal is buried into
high level of noise

Torsional Vibration Analysis Of Large Rotor System Using Finite-Element and MatLab Procedures

AMEEN AHMED NASSAR

Basrah Journal for Engineering Science, Volume 12, Issue 2, Pages 48-53

In this paper, the finite-element and the matlab procedures are used for the
torsional analysis of large rotor system. A large rotor system of 13 discs are
considered for the purpose of analysis. As a result, the finite-element and matlab
procedures are good tools for the analysis of vibration analysis and design of large
rotors and their results are accurate in comparison with other literatures. The normal
elastic curve and T-ω diagram obtained in this study are an effective illustration for
the vibration problems in large rotors, and the developed equation for drawing the
normalized elastic curve reduce the need for tabulated calculation of this curve and its
very essential for vibration analysts and designers.

A Study on Second Mode Stress Intensity Factor (KII) of Cracked Plates Under Compression Load

Nathera Abdual Hassan Saleh

Basrah Journal for Engineering Science, Volume 12, Issue 2, Pages 54-65

A two-dimensional finite element method for analysis and determination of second mode
stress intensity factor (KII) of several crack configurations in plates under uniaxial
compression is presented in this study. Various cases including diagonal crack (i.e. corner
crack, central crack as well as at different locations on the diagonal) and central kinked crack
are investigated with different crack's length, orientation and location. The influence of the
contact between two crack surfaces is taken into account by applying contact element
procedure with desired friction coefficient. The stress intensity factor is calculated by a crack
surface displacement extrapolation technique. From the obtained results of the analysis it is
found that, the corner cracked plates more dangerous than the other cracked plates, since it
has the highest stress intensity factor. Also, the length and orientation of the kinked crack
have significant effects on the stress intensity factor. The results of this investigation is
illustrated graphically, exposing some novel knowledge about the stress intensity factor and
its dependence on crack configuration.

Design and Implementation of Portable Vibration Analysis and Diagnosis System

Saleh I. Najem; Jaafar Kh. Ali; AbdelBaki Kh. Ali; Ali Hassan AbdelAali

Basrah Journal for Engineering Science, Volume 12, Issue 2, Pages 66-80

In this work, a portable vibration analysis and diagnosis system is designed and constructed.
The system is capable of doing most of the known analysis techniques such as FFT, time
waveform, cepstrum analysis, dual channel analysis, orbit, envelope detection and other
techniques. Furthermore, a new fast and efficient tracking analysis algorithm, suitable for
portable instruments, has been proposed. This technique provides the data required to get
accurate Bode and Nyquist plots for diagnostic analysis during machine run-up and coastdown
tests. Moreover, FFT waterfall and spectrogram techniques have been included. Also,
single-plane and dual-plane field balancing have been implemented in this system to execute
field balancing tasks

Synergistic Effect of Some Inorganic Corrosion Inhibitors for Carbon Steel in Cooling Water

Mudhaffar Y. Hussein; Haider J.Mohammed; Alaa A. Nagy

Basrah Journal for Engineering Science, Volume 12, Issue 2, Pages 81-88

The current approach to cooling water treatment is to use a multi – component inhibitors. Cooling
water formulations containing mixtures of inhibitors usually offer better and increased protection to
ferrous metals than similar concentrations of either of the individual components. Such mixtures are
synergistic in their action .But; the synergistic effects between nitrites, molybdates and inorganic
phosphate were not investigated until recently. A weight loss technique was used to investigate such
mixture and to optimize the concentrations of the components in the blend.Consequently; an
efficient and effective blend was developed as a corrosion inhibitor for carbon steel in aerated Al–
Daura refinery re-circulating cooling water in the pH range 6.75 to 7.25. The preferred
concentrations of components in the multi- component inhibitor blend (as ppm ) were: (SN + SM):
SHMP = 800: 20 with SN: SM weight ratio =3:2.The reduction in corrosion rate was 97.6 % .

Searching for Goal by Mobile Robot with Collision-Free Motion in Unknown Environment

Turki Y. Abdalla; Seaar J. Al; Duboni

Basrah Journal for Engineering Science, Volume 12, Issue 2, Pages 89-100

Obstacle avoidance and path planning are from the most important problems in mobile robots, especially in unknown environment . In this paper, we proposed an approach for mobile robot navigation combining path planning and obstacle avoidance. Methods such as obstacle avoidance are inspired from the nature, and have been developed by fuzzy logic to train an intelligent robot in unknown environment. The model of the robot has two driving wheels and the linear velocity and azimuth of the two wheels are independently controlled using PID controller. Inputs are obtained from ultrasonic sensors mounted on it.

The Sublime as Continuity System in Islamic Architecture -Mashhad Architecture as a Model-

Nasma Maan Mohammed; Rasha AbdUlKarim Ali

Basrah Journal for Engineering Science, Volume 12, Issue 2, Pages 101-119

Sublime is considered one of the significant concepts in the recent architectural thought; it has emerged clearly as a mean of creating the highest levels of continuity in architecture, especially in contemporary architectural movements. The importance of sublime especially has emerged. Many architectural studies dealt with concept of sublime in architecture is different and various ways according to the trend of each study; this shows the importance of studying the concept of sublime in the architectural field in general. This study tries to focus on the utilization of the sublime as heritage continuity system in Islamic Architecture because it’s important in the generation of sublimity of architectural models. The paper discusses the importance of this concept and its utilization in the designs, in order to explore the particular problem which has been represented as (The absence of a specific imagination of methods and strategies for achieving sublimation).Thus the objectives of the paper has been formed by building a theoretical framework consisting of two main items of detailed theoretical field which specifies sublime as a concept ,Firstly, Then the application of the important Islamic Architectural products in Mashhad Architecture as a model, Secondly, Finally, concluding utilization of sublime as dogmatically system in Mashhad Architecture, Thirdly, after discussing the results to formulate the conclusions in the end