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Laminated Composite Shells Are Widely Used In Civil, Aerospace And Other Engineering Applications, Largely Because Of Their Superior Mechanical Properties. Very Often These Composite Shells Undergo Large Deformation When Subjected To Severe Dynamic Loading Conditions. It Is Well-Known That When The Vibration Amplitude Becomes Comparable To Or Larger Than The Shell Thickness, The Nonlinear Interaction Between The Bending And Stretching Becomes Significant Inducing Geometric Nonlinearity. Cutouts Are Often Required In These Shells For Making Them Lighter, Ventilating, Inspecting, Providing Accessibility To Other Parts Of The Structure And Altering The Resonant Frequency. Effects Of Cutouts Are Likely To Be Considerable When The Structure Undergoes Large Deformation. During The Construction Of These Shells Or Later, Geometric Imperfections, If Present, Significantly Change The Nonlinear Vibration Behavior. Nonlinear Analysis Methods Are Required To Predict The Large Deformation Behavior. Among The Nonlinear Analysis Methods, The Finite Element Method Has Been Widely Used In Solving Nonlinear Problems Because Of Its Easy Implementation With Any Boundary Condition And Arbitrary Geometry. The Objective Of The Present Investigation Is To Study The Nonlinear Free Vibration And Transient Responses Of Laminated Composite Shells With/Without Cutouts And Geometric Imperfection Using The Finite Element Method. The Present Finite Element Formulation Considers Doubly Curved Shells And Von Kármán Type Nonlinear Strains Are Incorporated Into The First Order Shear Deformation Theory. The Governing Nonlinear Equations For The Free Vibration And Transient Responses Are Derived From Virtual Work Principle Based On Total Lagrangian Approach. These Equations Are Solved By Using The Direct Iteration Method For The Eigenvalue Problem For Free Vibration And Newmark Average Acceleration Method In The Time Integration In Conjunction With Modified Newton-Raphson Iteration Scheme For Transient Analysis. Appropriate Finite Element Code Is Developed For The Two Types Of Analyses As Mentioned Above Considering A C0 Eight-Noded Isoparametric Quadrilateral Element. The Code Is Validated By Comparing The Author’s Results Of Some Benchmark Problems Of Both Key Words: Nonlinear, Free Vibration, Transient, Shell, Cylindrical, Spherical, Hyperbolic Paraboloid, Laminated Composite, Cutout, Imperfection, Finite Element Method, Frequency Ratio, Amplitude Ratio, Geometric Nonlinearity