Fatigue failure is almost considered as the predominant problem affecting automotive parts under dynamic loading condition. Thus, more understanding of crack behavior during fatigue can strongly help in finding the proper mechanism to avoid the final fracture and extent the service life of components. The main goal of this paper is to study the fracture behavior of low carbon steel which is used mostly in automotive industry. For this purpose, the fractography of samples subjected to high and low stress levels in fatigue test then was evaluated and analyzed. Hardness and tensile tests were carried out to determine the properties of used steel. Also, the samples were characterized by microstructure test and XRD analysis to examine the constitute phases. The fatigue test (S-N curve) was done at stress ratio (R= -1), and the fracture examination was perform using Scanning Electron Microscope (SEM). The results of microstructure and XRD analysis were indicating that the Ferrite and a little amount of pearlite are the dominant phases of this steel. Whereas, the fractography observations reveal that the void coalescence ductile fracture is the main failure mode in samples with high stress level, while the ductile fracture (void coalescence) with Transgranular Cleavage fracture was noticed in low stress fatigue mode for this alloy.
Sought researcher to try to detect the type and size of the problems detected in or discovered or exposed or trying to find solutions to them as teachers and lecturers who are studying the educational, psychological and social articles in college studying these materials, whether the jurisdiction or extra materials, and clarified language definitions and terminology for search terms, indicating the importance of research into the problem of these either for teachers or for their students, and prepared a questionnaire organization questions open to get a clear responses and the Organization of the kind of problems faced by the lecturers and their students who are dealing with the educational, ps
... Show MoreThe problem of the current research has been crystallized through the study of the current reality of teaching Islamic Education in the intermediate schools. In order to get realistic results and to built on them the recommendations and suggestion that might help in improving teaching Islamic Education with more effective styles in the intermediate and secondary schools, this research has been formulated with the following question:
What are the common methods and styles used in teaching Islamic Education in the intermediate schools?
The importance of the research can be summarized as follows:
- The importance of the Islamic Education according to its
The aim of this research is to study the effect of using computer
techniques to increase students information at the experimenting the speed
control of dc motor by the magnetic field.
Simulation of the experiment has been used by implementing
“Electronics Workbench” software.
The random sample, included (30) second year electrical department
students, divided into two groups , experimental and control with pre-test and
post-test .
The results showed great advantages for the experimental group
through the use of computer program in the laboratory. The calculated (t) was
(10.6) which was significant and showed statistical differences between the
experimental and control group.
According to the result
Narrators who ruled Bukhari weak
In its great history, the small weak
And their strength Abu Hatim narrated by his son in his book wound and amendment
تواجه الوحدات الاقتصادية في العراق منافسة قوية بسبب مشكلات خاصة بإرتفاع الاسعار وارتفاع تكاليف الانتاج وضعف الاهتمام بدراسة السوق وغيرها من المشاكل ، فضلاً عن استخدام نظام التكاليف التقليدي الذي لا يوفر معلومات ملائمة لقرارات التسعير الامر الذي يتطلب دراسة وتحليل تلك المشكلات ومعالجتها بالاعتماد على تقنيات حديثة بما يمكنها من المنافسة ولهذا جاء هذا البحث والذي يعتبر من المداخل الحديثة لتخفيض التكاليف وم
... Show More