Higher-order Theory For Laminated Composite Plates And Analysis On Typical Configuration Of Aerocraft

This thesis first reviews the research status of laminated composite plate theories and the application of finite element software, and then discusses the development of laminated composite plate theories including the first-order theory which was used in finite element software. It is showed that the precision of finite element results obtained from finite element software will descend for thick composite structures, as the theory used in finite element software cannot satisfy continuity conditions of transverse shear stresses at interfaces. It is difficult to obtain three-dimensional elasticity solution for laminated composite structures with complicated boundary conditions, so that the global-local higher order theory will be developed to assess the finite element results predicted by finite element software. Advantages of the global-local higher order theory are that transverse shear stresses can be accurately predicted directly from constitutive equations without any postprocessing。Therefore, the C0 global-local higher-order theory for angle-ply composite plates is used for analysis of typical examples. Moreover, the results of global-local higher order theory in conjunction with three-dimensional elasticity solutions are used to assess the performance of elements used in ABAQUS. Numerical results showed that ABAQUS is able to accurately predict the bending response of laminated composite plates. In fact, laminated structures used in engineering is generally is enough thin, so ABAQUS is suitable for analysis of structures of composites in engineering.Finally, some structure of airplane are analyzed by using ABAQUS, and it is found that under the same rigidity stiffness requirement, weight of structures can be reduce 86% by using laminated composites instead of metallic materials. Meantime, the other excellent performances of laminated composites would be saved.Work of this paper can provide experiences for development of theory and application of ABAQUS in engineering, and some theoretical basis for designment of laminated composite structures used in airplane.