الفهرس 
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Abstract
Introduction: Fiber Reinforced Composite (FRC) is a composite material made of fiber reinforcement surrounded by a solid matrix. The many advantages of FRC, such as light weight, corrosion resistance, and the ability to vary its properties over a wide range of values; have made it to be used in many fields and many applications competitor to steel, concrete and wood. Although FRC has existed for many years, there is still much about it that needs to be understood before it becomes accepted and used safely in various applications as aerospace industry and a building material in civil engineering structures. The research problem: The results presented in literature indicate that the interaction among stacking sequence and cutout on the buckling behavior of laminated composites is needed to investigate in more details. Aim of the study: The objective of this study is either to identify the effects of cutout shape, boundary condition and to assess the impact of changing from a symmetric laminate to the anti-symmetric laminate on the buckling response of laminated composite plates. Study procedures: In this thesis a numerical study was carried out; First: To investigate the effect of symmetry and anti-symmetry laminate configuration, cutout and various boundary conditions, on the critical buckling load of fiber reinforced composite plates. The study includes two different initial laminate configurations ([90°/45°/−45°/0°]as and [90° /45°/−45°/0°]s) as initial fiber orientation [the subscript ‘as’ means anti-symmetric layer sequence and ‘s’ means symmetric layer sequence]. The cutout shape used is circular and semi-circular. The four boundary conditions in this study are (Clamped–Clamped [CC], Clamped–Pinned [CP], Pinned–Pinned [PP] and Clamped-Free [CF]). Second: Make optimization to optimize the fiber orientation (ply angle) and stacking sequence in order to maximize the critical buckling load of fiber reinforced composite plate. The objective function is to maximize the critical buckling strength and the design variables are the fiber ply angles. Finally: The initial buckling values and initial ply angles are compared with the optimal buckling values and optimal ply angles for the same boundary conditions. The thesis conclusions: The results obtained from this study will be beneficial to further studies about buckling characteristics of symmetric and anti-symmetric plates. Especially, it will be used to provide a comparison for new theoretical investigations. The results mirrored that the buckling load has been greatly affected by changing the boundary conditions. The maximum critical buckling load value is for clamped clamped boundary condition and the minimum value is for clamped free boundary condition. The buckling loads and fiber orientations of the laminated composite are calculated and optimized by ANSYS finite-element computer code.