This paper studies the effect of contact areas on the transient response of mechanical structures. Precisely, it investigates replacing the ordinary beam of a structure by two beams of half the thickness, which are joined by bolts. The response of these beams is controlled by adjusting the tightening of the connecting bolts and hence changing the magnitude of the induced frictional force between the two beams which affect the beams damping capacity. A cantilever of two beams joined together by bolts has been investigated numerically and experimentally. The numerical analysis was performed using ANSYS-Workbench version 17.2. A good agreement between the numerical and experimental results has been obtained. In general, results showed that the two beams vibrate independently when the bolts were loosed and the structure stiffness is about 20 N/m and the damping ratio is about 0.008. With increasing the bolts tightening, the stiffness and the damping ratio of the structure were also increased till they reach their maximum values when the tightening force equals to 8330 N, where the structure now has stiffness equals to 88 N/m and the damping ratio is about 0.062. Beyond this force value, increasing the bolts tightening has no effect on stiffness of the structure while the damping ratio is decreased until it returned to 0.008 when the bolts tightening becomes immense and the beams behave as one beam of double thickness.
the mental image is so important in human life as one of the major standers for his trends and behavior, and as the human nature requires to interest in things based on how much it’s close to and how much it effects on his interest, So the neighborhood countries was one of the topics that occupied the attention of the Iraqi individual and pushed him to form perceptions of them based on the cultural heritage and the historical relations of Iraq with these countries as well as the actions of neighboring countries on Iraq and the resulting effects on the course of events. the mental image is so important in human life as one of the major standers for his trends and behavior, and as the human nature requires to interest in things bas
... Show MoreRepresents light a sovereign and importance in cinematography element of what possessed the physical characteristics make it a sharp image detail or opaque, or any other form as he wants the director, Valdu away from the main function, which emerged with the beginnings of cinema, any access to endanger the proper and good, the Alachtgalat dramatic and psychological are deepened performance lighting and functioned in adjacent with the shadows, all the two complement each other, which affects the image details or even the ability to express their personal depths or the social and psychological same place, and this prompted the researcher to determine the search in the following address: (employing lighting to express their personal duplica
... Show Moremany painters tried to mix colors with Music by direct employment through colorful musical pieces or the use of multiple instruments and techniques , or vice versa, including the French artist )Robert Stroben(, he transferred the piece of music to be depicted on the painting and worked on the tones of music (Johann Sebastian Bach) by dropping the color on the lines of the musical scale, for example (the C tone) ranging from brown to red ( Tone La A) from gray to orange, and so on, the presence of links and similarity factors between the world of music and the world of colors facilitated the process of linking musical notes with colors, the most famous of which was presented by the world (Newton) in the circle of basic colors and linking
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The research aimed to prepare an audit program focusing on the activities of municipal institutions related to the environmental dimension as one of the dimensions of sustainable development, and applying the program for the purpose of preparing an oversight report related to assessing the impact of the activities of municipal institutions on the environmental reality as the main channel through which municipal institutions contribute to achieving the part related to it. Among the requirements of sustainable development, the proposed program was prepared and applied to the institutions affiliated to the Directorate of Mu
... Show MoreThe research aims to identify the effect of teaching according to the augmented reality on the technique of the visual thinking skills among scientific fifth-grade students in a biology course. In order to achieve the goal of the research, the researcher adopted the experimental approach with the partial set of the two equal groups with the dimensional test of visual thinking skills, The research population represented all the scientific students of the fifth grade for morning government schools affiliated to the General Directorate of Education of Baghdad / Karkh II, alshakerin preparatory for boys was chosen intentionally, in which two groups were chosen for this study, one group is chosen randomly as the control group via lottery, whe
... Show Moreملخص البحث
تبحث الدراسھ عن تنفیذ افضل لمفھوم التعلم مدى الحیاة كھیكل موجھ للسیاسة التربویة في العراق بشكل عام وفي
التعلیم العالي بشكل خاص. تحدد الدراسة استراتجیات التعلم مدى الحیاة وتناقش اھمیتھ وسماتھ الرئیسیة لتسھیل
الوصول الى فرص تعلم متمیز و ملائم لحاجات الطلبة مدى الحیاة، كما تناقش دور الجامعة في تحقیق ھذا الھدف.
Abstract search seeks to clarify the role and the importance of financial and fiscal policy adopted by the Iraqi Government during the years (2015 – 2018) to meet federal public deficit, as the Iraqi economy to shocks from falling global oil prices and terrorist attack ISIS, so the State budget suffered from a severe lack of income as a result of its reliance on revenues from selling crude oil and in return the high proportion of public expenditures. Especially military to counter these attacks that by studying the results of the implementation of budgets and analysis and statement Causes of disabilities and assessment of these policies and procedures imposed by the International Monetary Fund. the research aims to show how increased g
... Show MoreThis research aims to determine the concentration of radionuclides in dust samples on the public streets of the small side of Diwaniyah city in Iraq as a result of movements of wheels and cars using the gamma spectra and high purity germanium detector (HPGe) with resolution of (2.3 keV) for energy (1.332 MeV) of cobalt 60Co. Dust samples were collected from the streets Diwaniyah city with (26) samples prepared for measurement. The results of the specific activity concentration of Uranium-238, Thorium-232, Potassium-40 and Cesium-137 were (14.66 ± 0.950, 26.29 ± 2.431, 219.04 ± 15.150 and 11.49 ± 0.876) Bq/kg respectively. The radiation parameters Rae
This research aims to clarify the advantages of using the regression method as analytical procedure in the tax audit to reducing the examination cost , time, effort, human and material resources, and represents an applied study in the General Commission of taxes. In order to achieve its objectives the research has used in the theoretical side the descriptive approach (analytical), and in the practical side regression method has been applied to the research sample represented by the soft drinks company that is subject to the tax settlement for the year 2014, where the value of sales has been verified by using the regression method without conductinga comprehensive examination. The most important results of the research indicate that the r
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