Luận án Tiến sĩ: Ổn định đàn hồi phi tuyến của kết cấu công trình dạng tấm vỏ FG-CNTRC có tính tới các biện pháp tăng cứng

The stability analysis of thin-walled structures is crucial in engineering, particularly for designs involving large deformations. With the rapid advancement in materials science, Functionally Graded Carbon Nanotube-Reinforced Composites (FG-CNTRC) have emerged as promising candidates for structures operating under harsh conditions due to their superior thermomechanical properties compared to traditional materials. However, their complex anisotropic behavior necessitates rigorous theoretical and numerical investigations before widespread application. Enhancing the load-bearing capacity of these advanced plate-shell structures often involves stiffening measures like ribs. This study addresses the critical need for a comprehensive understanding of the nonlinear elastic stability of such complex structures, especially under various loading conditions and thermal environments.

Researchers and graduate students in structural mechanics, composite materials, and advanced civil/aerospace engineering.

This doctoral thesis meticulously investigates the nonlinear elastic stability of advanced plate-shell structures made from Functionally Graded Carbon Nanotube-Reinforced Composites (FG-CNTRC), emphasizing the impact of various stiffening measures and environmental conditions. The study systematically develops theoretical frameworks and analytical solutions to predict the behavior of these structures under diverse scenarios. Chapter 1 provides an overview of nanocomposite materials, specifically FG-CNTRC, their unique properties, and existing research on their thermomechanical response. It identifies gaps related to stiffened FG-CNTRC plate-shell structures. Chapter 2 delves into the nonlinear stability of FG-CNTRC cylindrical shell structures stiffened by FG-CNTRC ribs under external pressure or axial compression within a thermal environment. It establishes governing equations and boundary conditions, conducting detailed analyses and comparative studies. Chapter 3 extends this investigation to cylindrical shells subjected to torsion, exploring stiffening by both FG-CNTRC ribs and novel Auxetic cores. This chapter examines the design of these composite structures and their nonlinear equilibrium equations under torsional loads. Finally, Chapter 4 focuses on the nonlinear stability of FG-CNTRC orthotropic plates reinforced with FG-CNTRC ribs under combined loading conditions, employing a higher-order shear deformation theory for enhanced accuracy. The research's primary contributions lie in establishing comprehensive analytical models and numerical methods for predicting the buckling and post-buckling behavior of these complex composite structures. The findings offer valuable insights into optimizing the design of FG-CNTRC components for aerospace, civil, and mechanical engineering applications where lightweight, high-strength, and thermally resistant structures are critical. This work contributes significantly to the understanding and application of advanced composite materials in load-bearing structures, guiding future material and structural design innovations.