Author

Swetha Suresh

Date of Award

Spring 2019

Document Type

Thesis - Open Access

Degree Name

Master of Science in Aerospace Engineering

Department

Graduate Studies

Committee Chair

Dr. Habib Eslami

First Committee Member

Dr. Sirish Namilae

Second Committee Member

Dr. Mandar Kulkarni

Comments

Functionally graded materials, a subcategory of Advanced Composite Materials, is characterized by variation in microstructure and properties across the thickness of the beam. The unique advantage of Functionally Graded Materials (FGM) is the smooth and continuous change in properties of constituent materials from one layer to its adjacent layer in comparison to sharp changes in material properties as seen in composites. This unique attribute of functionally graded materials thereby, reduces the stress concentrations, shear and thermal stresses that occur at the interference of layers. Functionally graded materials can, thus, find applications in areas subjected to high mechanical loads and thermal stresses. The scope of this thesis is twofold: first, to study the nonlinear static analysis of FGM beams subjected to uniformly distributed mechanical transverse pressure load with both conventional and unconventional boundary conditions. The conventional boundary conditions considered here, are simply supported and clamped-clamped with immovable edges, and unconventional boundary conditions considered are translational and rotational springs. The reason for considering unconventional boundary conditions is that in practice, it might be very difficult to achieve rigidly simply-supported or rigidly clamped boundaries. The effect of first order shear deformation theory is also considered. Second, is to study the nonlinear bending analysis of FGM beams subjected to both thermal loads and uniformly distributed mechanical transverse pressure load, for clamped-clamped beams with immovable edges. Volume fraction of component materials is varied using power law across the thickness. Material modeling has been done using two different models, namely: rule of mixtures and Mori-Tanaka model. Nonlinear governing equations were obtained using the von Karman geometric nonlinearity and first-order shear deformation theory. Results are obtained for variations with different gradation patterns. A few of the obtained results are compared with Finite Element Results that are obtained using ABAQUS software.

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