Pre-processing for isogeometric analysis of laminated composites

Resumo

Composites are materials resulting from the mixture of two or more components, usually a polymer matrix reinforced with synthetic fibers, used to build stronger structures capable of withstanding heavy loads and unfavorable environmental conditions. Laminated shells are made of layers of fiber-reinforced composite material, stacked in a specific sequence to ensure good structural performance. The analysis of these structures is predominantly done using the Finite Element Method, a conventional approach used to solve these problems, approximating both the displacements and the geometry of the structure using polynomial functions. A more recent alternative is Isogeometric Analysis (IGA), which uses rational functions to approximate the displacements and geometry of the structure. This ensures that the geometry of the problem is exact, regardless of the level of discretization used. The aim of this work is to study the use of NURBS surfaces in the context of isogeometric analysis of laminated structures. The theoretical and practical aspects of these representations will be studied, with emphasis on the pre-processing stage of the numerical analysis. In this context, the pre-processing of the numerical model of the composite material structure is carried out in the academic software FEMEP (Finite Element Method Educational Computer Program), written in the Python language. The software's graphical interface has been extended to handle models of laminated composite plates. The numerical model is processed using the FAST tool, where the pre-processing program writing routines have been implemented. In the post-processing stage, the simulation results are visualized using the Nlpos tool. The system developed was used in examples of laminated plates, demonstrating the system's capabilities.