Luận án Tiến sĩ Cơ kỹ thuật: Phát triển phương pháp phần tử hữu hạn đẳng hình học để phân tích và điều khiển đáp ứng kết cấu tấm nhiều lớp

Trong luận án này, một công thức phần tử hữu hạn đẳng hình học được phát triển dựa trên trích xuất Bézier để giải quyết các bài toán tấm khác nhau, sử dụng lý thuyết biến dạng cắt bậc cao 7 bậc tự do cho cả phân tích và điều khiển đáp ứng của các cấu trúc tấm. Một điểm mới trong luận án này là sử dụng trích xuất Bézier. Trong phân tích đẳng hình học thông thường, các hàm cơ sở B-spline hoặc hàm trải rộng trên toàn bộ miền của các cấu trúc chứ không chỉ là một miền cục bộ như các hàm hình dạng Lagrangian trong FEM.
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Luận án Tiến sĩ Cơ kỹ thuật: Phát triển phương pháp phần tử hữu hạn đẳng hình học để phân tích và điều khiển đáp ứng kết cấu tấm nhiều lớp THE WORK IS COMPLETED AT HCM CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION Supervisor 1: Assoc. Prof. Dr NGUYEN XUAN HUNG Supervisor 2: Assoc. Prof. Dr DANG THIEN NGON PhD thesis is protected in front ofEXAMINATION COMMITTEE FOR PROTECTION OF DOCTORAL THESIS HCM CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION, Date .... month .... year ..... ORIGINALITY STATEMENT I, Nguyen Thi Bich Lieu, hereby assure that this dissertation is my ownwork, done under the guidance of Assoc. Prof. Dr. Nguyen Xuan Hung and Assoc.Prof. Dr. Dang Thien Ngon with the best of my knowledge. The data and results stated in the dissertation are honest and were not beenpublished by any works. Ho Chi Minh City, October 2019 Nguyen Thi Bich Lieu i ACKNOWLEDGEMENTS This dissertation has been carried out in the Faculty of Civil Engineering, HCMCity University of Technology and Education, Viet Nam. The process of conductingthis thesis brings excitement but has quite a few challenges and difficulties. And I cansay without hesitation that it has been finished thanks to the encouragement, supportand help of my professors and colleagues. First of all, I would like to express my deepest gratitude to Assoc. Prof. Dr.Nguyen Xuan Hung and Assoc. Prof. Dr. Dang Thien Ngon, especially Assoc. Prof.Dr. Nguyen Xuan Hung from CIRTech Institute, Ho Chi Minh City University ofTechnology (HUTECH), Vietnam for having accepted me as their PhD student andfor the enthusiastic guidance and mobilization during my research. Also, I would liketo sincerely thank Dr. Thai Hoang Chien, a close brother, for his helpful guidance atfirst step of doing research and his support for my overcoming of the hardest time. Secondly, I would like also to acknowledge Msc. Nguyen Van Nam, Faculty ofMechanical Technology, Industrial University of Ho Chi Minh City, Vietnam fortheir troubleshooting and the cooperation in my study. Furthermore, I am grateful toChau Nguyen Khanh and the staffs at CIRTech Institute, HUTECH, Vietnam for theirprofessional knowledge, interactive discussion, and immediate support. Thirdly, I take this chance to thank all my nice colleagues at the Faculty of CivilEngineering, Ho Chi Minh City University of Technology and Education, for theirprofessional advice and friendly support. Finally, this dissertation is dedicated to my family, especially my belovedhusband, who has always given me valuable encouragement and assistance. Nguyen Thi Bich Lieu ii ABSTRACT Isogeometric analysis (IGA) was introduced in 2005 by Hughes et al. [5] as abreakthrough in numerical simulation. The main advantage of the IGA is to use thesame basis function to describe the geometry and to approximate the problemunknowns. It integrates Computer Aided Design (CAD) and Computer AidedEngineering (CAE) and so far the effectively numerical tool for the analysis of avariety of practical problems. The computational cost is decreased significantly as themeshes are generated within the CAD. IGA produces the results with higher accuracybecause of the smoothness and the higher-order continuity between elements. For thelast decade of development, isogeometric analysis has surpassed the standard finiteelements in terms of effectiveness and reliability for various problems, especially forthe ones with complex geometry. Owing to its important role in many engineering structures and modernindustries, laminated plate structures are widely used in a diverse array of structuresin many areas such as aviation, shipbuilding and civil engineering. Laminated plateshave excellent mechanical properties, including high strength to weight and stiffnessto weight ratios, wear resistance, light weight and so on. Besides possessing thesuperior material properties, the laminated composites also supply the advantageousdesign through the arrangement of the stacking sequence and layer thickness to obtainthe desired characteristics, that’s why they have received considerable attention ofmany researchers worldwide. In this dissertation, an isogeometric finite element formulation is developedbased on Bézier extraction to solve various plate problems, using a seven-dof higher-order shear deformation theory for both analysis and control the responses of platestructures. One key point in this dissertation is to exploit the distinctive advantage ofBézier extraction in ...