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التحقيق التجريبي والعددي للصفائح الرقيقة المثقوبة تحت الشد == Experimental And Numerical Investigations of Thin Tensioned Plates With Holes
Author name:
ارشد عبد الله راشد
Supervisor name:
كريم محسن يونس
General topic:
Production engineering metallurgy and materials
Specific topic:
Production Engineering
Degree:
Master
University:
University of Technology
Language:
English
University location:
Baghdad
First pages:
50T167 - p.pdf
Abstract:
ان الصفائح المثقوبة تستخدم عالميا في تصنيع الھياكل في التطبيقات الميكانيكية والانشاءات كمثال على ذلك ھياكل الطائرات والتراكيب الطبية ووصلات الربط الخ. ومن المعروف جيدا ان استعمال الثقوب في الھياكل المجھدة تولد اجھادا موقعيا عاليا في منطقة من الثقب تعرف بم | The plates with holes are used in cosmopolitan for manufacturing structures in mechanical and civil engineering applications like aircrafts, medical structures, joint connection applications etc. It is well known that utilizing holes in stressed structures produces highly localized stresses at area of the holes known as the stress concentration area,which leads to reduce the mechanical strength of the structures.The main objective of this study is to investigate the effect of three parameters on the stress concentration factor in plate with two holes having different size holes and subjected to uniaxial tension. The three parameters include firstly, the location of holes when oriented with respect to axis of loading, parallel, transverse and inclined with line of uniaxial tension load at different angles. Secondly, the aspect ratio for the hole size (large to small radius).The last parameter effect is the distance between two holes.Numerical simulation using finite element method for two - dimensional model is developed to determine the maximum value of Von Mises stress with commercial software package ANSYS V.11.The experimental photoelastic technique is carried out on fabricated polycarbonate model loaded in one direction. From the analysis of the results, it is found that the maximum stress concentration factor is at the point tangent to the edge of the hole. The comparison between the finite element method and experimental photoelastic technique results showed the stress concentration factor, which obtained experimentally and with finite element method are congruent, since the maximum variation between the two results is about 7.03% As well as the highest and lowest value of the stress concentration factor equal to 3.1973, 2.0640 at value of angle 60°, 90° respectively.It is recommended from the above conclusions that manipulating the three parameters which effect the stress concentration factor are namely, holes position, size, and distance between two holes on the plate that used in the application will play essential role to reduce the value of stress concentration factor which subsequently crucially minimize or avoid fast failure. This can be translated into saving precious lives preventing money wastage due to structures damage ending into catastrophe.
