اجريت مناقشة رسالة طالب الماجستير (بسيم بريسم ظاهر) على قاعة قسم الهندسة المدنية في جامعة النهرين والموسومة
“تحليل المسقفات الصفائحية المضلعة متبانية السمك وأرضيات الجسور الخلوية رقيقة الجدران بطريقة الشرائح المحددة ذوات دوال التخديد
وتألفت لجنة مناقشة رسالة الطالب من التدريسيين المدرجة أسمائهم في ادناه:
1- أ.م. د. عادل عبد الأمير محمد (رئيسا)
2- أ.م. د. أحمد عبدالله منصور (عضوا) (جامعة ديالى)
3- م.د. رائد أحمد داود(عضوا)
4- أ.م.د. ليث خالد كامل الحديثي (عضوا و مشرفاً).
وحصل الطالب على درجة امتياز..
يتلخص البحث كما يلي:
This study presents a structural analysis of longitudinal roofs consisting of variable-thickness folded plate roofs linked to each other at their longitudinal ridges, and cellular bridge decks made up of thin-walled box-section beams through using the spline finite strip method. The most important characteristics of these two types of structural systems are the inclusion of two main actions: the act of plate bending action and the plane stress action at the same time. Those structural actions have been analyzed simultaneously in this study by the approach of using finite strips with B3-spline representation of the longitudinal displacement function.
Because of regularity in axial direction of the longitudinal folded plate roofs and bridge decks, the most suitable method to analyze them is the finite strip method (FSM), especially with the use of longitudinal extension functions (spline functions) instead of chain functions that require a number of harmonics which unfavorably double the dimensions of stiffness matrix as many times as the number of harmonics. That difficulty in the conventional FSM makes the present SFSM the most efficient and practical in the analysis of exceptional cases of folded plate roofs and bridge decks, such as skewed plate cases, various types of end supports, and pointers (intermediate columns).
MATLAB computer package has been used to analyze the folded plate roofs and bridge decks by a code named (Variable-Thickness Folded Plate B3-Spline Finite Strip Method) (VFB3SFSM). Actually, the B3-spline function has been operated to express the displacement function in the longitudinal direction of strips and to check their efficiency.
Thereafter, the programmed SFSM is made verification and applied to the analysis of four different cases. The first case was an opened variable-thickness folded plate structure and the second case was a double T-beam and slab bridge model, while the third case was a two-cell box girder bridge deck with two simply supported ends and two cantilever plates having variable thickness, finally, the forth case was a continuous variable-thickness folded plate structure with unequal two spans. Deflection, stress and bending moment results in both longitudinal and transfers sections are compared with evidences of some authorized theoretical and experimental results, and some developed discrete-element methods where very high agreements are acquired. In accurate, the overall differences in deflection values obtained by SFSM the does not exceed the margin of 11% in comparison with the (conventional FSM with high number of harmonics), and 16.5% in comparison with the finely meshed finite element method, while the bending moment differences did not exceed 18.5% In the worst of circumstances.
As a final result drawn from this study will likely be nominated the present SFSM to further beyond simplicity conditions with preserving the accuracy of the results and shortening the time.
