Ph.D. Tezi Görüntüleme

Student: Umut TOPAL
Supervisor: Prof. Dr. Ümit UZMAN
Department: İnşaat Mühendisliği
Institution: Graduate School of Natural and Applied Sciences
University: Karadeniz Technical University, Turkey
Title of the Thesis: Optimization Of Laminated Composite Plates Using Modified Feasible Direction Method
Level: Ph.D.
Acceptance Date: 3/7/2008
Number of Pages: 144
Registration Number: Di643

       In this study, the applicability of the modified feasible direction method on the optimization problems of laminated composite plates is investigated. Therefore, four different optimization problems such as strength, frequency and bucklings under mechanical and thermal loads for some parameters are considered. On the other hand, some parameters which were neglected in the previous studies are considered in this study to obtain reliable and realistic results. The thesis prepared with this scope, includes the following chapters.

In the first chapter, general information about composite materials is given in detail. On the other hand, the stress-strain relations for a lamina, equilibrium equations, finite element formulations based on the first-order shear deformation theory, failures of laminated plates, optimization and optimization methods used in this study are given. The importance of the matter, selection of the model, technique of the analysis and the previous studies about this subject are given.

       In the second chapter, the basic equations for four types of optimization problems are given. Besides, the general information and basic equations used for some parameters are also presented in this chapter.

In this third chapter, the response values obtained from optimization of laminated composite plates for four different problems are discussed in detail. After that, some conclusions of the research and recommendations for the future works are given.

       As a conclusion, it is emphasised that the modified feasible direction method is efficient and reliable method for optimization problems of laminated composite plates, but this method must be applied to the other optimization problems of the laminated plates for approving the efficiency and reliability. On the other hand, the parameters considered in this study affect the optimum results substantially and therefore they must be taken into account at the optimum design stage of the laminated plates.

Keywords: Laminated composite plates, First-order shear deformation theory, Optimization,

       Modified feasible direction method, Strength, Frequency, Buckling.