Preferred Language
Articles
/
alkej-14
Free Vibration Analysis for Dynamic Stiffness Degradation of Cracked Cantilever Plate
...Show More Authors

 

In the present work a dynamic analysis technique have been developed to investigate and characterize the quantity of elastic module degradation of cracked cantilever plates due to presence of a defect such as surface of internal crack under free vibration. A new generalized technique represents the first step in developing a health monitoring system, the effects of such defects on the modal frequencies has been the main key quantifying the elasticity modulii due to presence any type of un-visible defect. In this paper the finite element method has been used to determine the free vibration characteristics for cracked cantilever plate (internal flaws), this present work achieved by different position of crack. Stiffness reduction in term of elastic material properties is analyzed through a parametric study of crack density factor. Results are given for Young’s modulus and shear modulus variation with respects the vibrational characteristics.                        

 

 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Dec 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
Analysis of the competitiveness for commercial banks in Iraq for a period of 2004 – 2012
...Show More Authors

This study was conducted on a sample of commercial banks in Iraq, chosen according number of considerations for twenty banks, contained two public banks and eighteen private banks.                                                                                             &

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Sep 01 2007
Journal Name
Al-khwarizmi Engineering Journal
Flutter Speed Limits of Cantilever Rectangular and Tapered Plates
...Show More Authors

The aerodynamic and elastic forces may cause an oscillation of the structure such as the high frequency of the airfoil surfaces and the dynamic instability occurring in an aircraft in flight and failure may occur at a speed called flutter speed. In this work, analytical and numerical investigations of flutter limits of thin plates have been carried out. The flutter speed of rectangular plates were obtained and compared with some published results. Different design parameters were investigated such as aspect ratio, thickness and their effects on flutter velocity. It was found that the structural mode shape plays an important role in the determination of the flutter speed and the coupling between the bending and torsional mode is the main

... Show More
View Publication Preview PDF
Publication Date
Wed Apr 20 2022
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Simulation and Analysis the Effect of the Lorentz Force in a Free Electron Laser
...Show More Authors

Due to the scientific and technical development in the free electron laser devices and the accompanying industrial and technological progress in various fields of civil and military life, it became necessary to expand the understanding of the mechanism of interaction of electrons (as an effective medium) with the magnetic field that they pass through to form coherent photons.

    In this paper, the Lorentz force effect is simulated and analysed. The results showed that the Lorentz force originates from the magnetic field, making the electron move through it oscillate. This sinusoidal motion of the electron causes it to emit two photons for every electron wavelength. It has been concluded that the electron velocity directly affe

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Wed Dec 31 2014
Journal Name
Iraqi Journal For Computers And Informatics
Gate Control System for New Iraqi License Plate
...Show More Authors

This paper presents an approach to license plate localization and recognition. A proposed method is designed to control the opening of door gate based on the recognition of the license plates number in Iraq. In general the system consists of four stages; Image capturing, License plate cropping, character segmentation and character recognition. In the first stage, the vehicle photo is taken from standard camera placed on the door gate with a specific distance from the front of vehicle to be processed by our system. Then, the detection method searches for the matching of the license plate in the image with a standard plate. The segmentation stage is performed by is using edge detection. Then character recognition, done by comparing with templ

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Thu Feb 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Compare between result of analysis of variance after and before use analysis covariance to Split-blocks design
...Show More Authors

This research aims to study the important of the effect of analysis of covariance manner for one of important of design for multifactor experiments, which called split-blocks experiments design (SBED) to deal the problem of extended measurements for a covariate variable or independent variable (X) with data of response variable or dependent variable Y in agricultural experiments that contribute to mislead the result when analyze data of Y only. Although analysis of covariance with discussed in experiments with common deign, but it is not found information that it is discussed with split-Blocks experiments design (SBED) to get rid of the impact a covariance variable. As part application actual field experiment conducted, begun at

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jul 01 2018
Journal Name
Journal Of Educational And Psychological Researches
Analysis of computer textbooks content for preparatory stage according to the logical thinking
...Show More Authors

The study aims to analyze computer textbooks content for preparatory stage according to the logical thinking. The researcher followed the descriptive analytical research approach (content analysis), and adopted an explicit idea during the analysis process. One of the content analysis tools which was designed based on mental processes employed during logical thinking has utilized to figure out the study results. The findings revealed that logical thinking skills formed (52%) in fourth preparatory textbook and (47%) in fifth preparatory textbook.     

View Publication Preview PDF
Publication Date
Tue Mar 30 2021
Journal Name
Baghdad Science Journal
Experimental Evidence of Chaotic Resonance in Semiconductor Laser
...Show More Authors

In this paper, an experimental study has been conducted regarding the indication of resonance in chaotic semiconductor laser.  Resonant perturbations are effective for harnessing nonlinear oscillators for various applications such as inducing chaos and controlling chaos. Interesting results have been obtained regarding to the effect of the   chaotic resonance by adding the frequency on the systems. The frequency changes nonlinear dynamical system through a critical value, there is a transition from a periodic attractor to a strange attractor. The amplitude has a very relevant impact on the system, resulting in an optimal resonance response for appropriate values related to correlation time. The chaotic system becomes regular under

... Show More
View Publication Preview PDF
Scopus (4)
Scopus Clarivate Crossref
Publication Date
Tue Feb 01 2022
Journal Name
Journal Of Engineering
Nonlinear Finite Element Analysis of Fiber Reinforced Concrete Pavement under Dynamic Loading
...Show More Authors

The analysis of rigid pavements is a complex mission for many reasons. First, the loading conditions include the repetition of parts of the applied loads (cyclic loads), which produce fatigue in the pavement materials. Additionally, the climatic conditions reveal an important role in the performance of the pavement since the expansion or contraction induced by temperature differences may significantly change the supporting conditions of the pavement. There is an extra difficulty because the pavement structure is made of completely different materials, such as concrete, steel, and soil, with problems related to their interfaces like contact or friction. Because of the problem's difficulty, the finite element simulation is

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Mon Nov 01 2021
Journal Name
Chaos, Solitons & Fractals
Dynamic analysis of a harvested fractional-order biological system with its discretization
...Show More Authors

View Publication
Scopus (23)
Crossref (15)
Scopus Clarivate Crossref
Publication Date
Thu Sep 01 2016
Journal Name
Journal Of Engineering
Sliding Mode Vibration Suppression Control Design for a Smart Beam
...Show More Authors

Active vibration control is the main problem in different structure. Smart material like piezoelectric make a structure smart, adaptive and self-controlling so, they are effective in active vibration control. In this paper piezoelectric elements are used as sensors and actuators in flexible structures for sensing and actuating purposes, and to control the vibration of a cantilever beam by using sliding mode control. The sliding mode controller (SMC) is designed to attenuate the vibration induced by initial tip displacement which is equal to 15 mm.  It is designed based on the balance realization reduction method where three states are selected for the reduced model from the 24th states that describe the c

... Show More
View Publication Preview PDF