The Study Of Delamination Damage Of Laminated Composite Cylindrical Shells

The composite, due to its high performance on specific strength, specific stiffness, fatigue resistance, corrosion resistance and good designability, have been widely used in industrial applications such as aerospace, medical building, automobile and civil engineering. However, the delamination which was inevitably during its manufacturing and applications, would greatly affect the strength and stiffness of structure and so on. Therefore, the research on the mechanical characteristic of laminated composite structures with delamination damage has theoretical and applicable value.The Hamilton canonical equation and the semi-analytical solution are applied to the numerical study on delamination damage of laminated composite cylindrical shells in this paper:Firstly, the Hamilton canonical equations of elastic material in cylindrical coordinate are deduced by using basic equations of elasticity method and Hellinger-Reissner (H-R) variational principle method.Secondly, the Hamiltonian elements of the clamped supported, simply supported and symmetric boundary conditions are derived from H-R variational principle method. The three-dimensional model of laminated composite shells with some boundary conditions has been established. Comparison with available data shows that the numerical method in this thesis is accurate and effective.Finally, based on the semi-analytical solution of Hamilton canonical equation, a three dimensions model for the composite laminated cylindrical open shell with a rectangular delaminating is established by using the separating-combining method, and some examples are calculated. Meanwhile, in term of the model of the semi-analytical solution, the fracture rule of strain energy release rate is derived by fracture mechanics.