In the preliminary stage of the industrial design, the structural analysis of the components made of composite materials is generally difficult to carry out for aircraft structures having complex three-dimensional geometry. More importantly, in the case of composite structures, the lay-up process creates a particular distribution of the material properties that is challenging to simulate in a virtual environment. This research work is, therefore, focused on the use of the finite element method for the numerical analysis and the structural redesign of the bulkhead and flap aircraft components. In particular, the numerical results obtained in this work are the stress and strain fields of these mechanical components. The redesign and the structural optimization of these two mechanical components are performed employing a simple numerical procedure. For this purpose, the quality of the stress and strain fields obtained by performing numerical experiments is evaluated considering failure criteria suitable for composite structures. Subsequently, the analysis developed in this study is used for determining the performance of the material as well as the number and orientation of the plies selected for the composite components. The verification process performed in this work, on the other hand, consisted of a comparative analysis with the same aerospace components made of isotropic and anisotropic materials. The numerical results found are compared with the experimental results available for the aerospace components that are geometrically and functionally similar to the bulkhead. In general, a good agreement is found in the comparison between the numerical and experimental results.