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العنوان
Behaviour of Bolted Pipe Splices with Circular Pattern /
المؤلف
Ibrahim, Ahmed Mostafa Mohamed.
هيئة الاعداد
باحث / أحمد مصطفى محمد ابراهيم
مشرف / عبد الرحيم خليل دسوقى
مشرف / شريف عبد الباسط ابراعيم
مناقش / تامر حنفى رضوان
تاريخ النشر
2021.
عدد الصفحات
275p. :
اللغة
الإنجليزية
الدرجة
الدكتوراه
التخصص
الهندسة المدنية والإنشائية
تاريخ الإجازة
1/1/2021
مكان الإجازة
جامعة عين شمس - كلية الهندسة - الهندسة الانشائية
الفهرس
Only 14 pages are availabe for public view

from 275

from 275

Abstract

Moment resisting connection are widely used nowadays in different applications. The use of circular hollow sections (CHS) have increased due to its aesthetic appearance and good mechanical properties. Attention should be given to their connections under different loading conditions to achieve greater flexibility for its use.
CHS splices can be achieved either using a ring flange or a solid end plate. This research investigates the behavior of the bolted CHS splices with solid circular end plates under pure bending moment that allows the use of CHS as long flexural members. As the study focuses on small-to-medium diameters, number of bolts considered are 6, 8 and 10 bolts to fulfill code requirements for bolt spacing.
Eight connections are experimentally tested and the corresponding finite element models are constructed. The finite element models are verified with the experimental results and showed acceptable agreement in terms of both ultimate moment capacity and load-displacement curves. Three modes of failure are observed where the first is pure bolt failure, the second is pure end plate yielding while the third is a combination of the two modes where end plate plastifies accompanied by bolt failure. Stiffness is also observed and is found to be greatly affected by the thickness of the end plate. Increasing the number of bolts in the end plate does not have such significant effect on the connection stiffness while it increases its moment capacity. Contact stresses between the two end plates are observed and the axis of rotation can be conservatively considered tangent to the CHS at its compression side. This concept can be considered for end plate yielding analysis used in the mathematical model developed through the study.
Despite the importance of the splices of CHS under flexure, its design procedures are not addressed in any of the international codes. Setting up a design
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procedure for the design of solid end plate splices requires analytical models for both the end plate yielding capacity and the bolts group capacity. Using the verified finite element model, an extensive finite element study is conducted to cover major connection geometrical parameters. An analytical model based on modified T-stub analogy is used to determine the yielding capacity of the end plate and its results showed acceptable agreement with the finite element study. As well, a statistical model is proposed to account for the inelastic behavior of the bolts group and the varying location of the axis of rotation, to determine its ultimate capacity. Design procedures and recommendations are proposed based on the finite element analysis (FEA) results and both the analytical and statistical studies.
Although the main study focuses on small-to-medium CHS diameters and the practical solution for splicing the large diameter CHS is the ring flange, yet, a short study has been carried out to investigate the behavior of large diameters splices with solid end plates.
According to the study a more comprehensive study has to be carried out as the behavior of large diameter CHS differs greatly from the behavior of small-to-medium diameters behavior.
Effect of stiffeners on both small-to-medium and large diameter CHS splices has been investigated and found to have a great effect on the ultimate capacity and the stiffness of the splice