FAST ModDef: An interative software for pre-processing Finite Element and Isogeometric Models of Composite Stuctures

Resumo

The finite element method (FEM) is a numerical method widely used for structuralanalaysis, specially in the case of structures with complex material, loading and supportconditions. In FEM based simulation systems, the pre-processing stage involves theconstruction of geometric model using a interactive CAD module, the construction ofanalysis model using a mesh generation module, and definition and application ofanalysis attributes (simulation parameters, material properties, loads and supports). Incontext of the Isogeometric Analysis approach, the underlying mathetical representationsadopted in geometric modeling are also used in the simulation formulation, as RationalBézier Surfaces and NURBS, eliminating the geometry approximation error presented inclassical FEM and providing superior refinement capabilities (hpk-refinements). Having aproper interactive graphic system is crucial for pre-processing finite element models. Thispaper presents FAST ModDef, an academic pre-processing FEM tool for strcuturalanalysis of isotropic and composite structures, for FAST (Finite element AnalySis Tool)created at Laboratório de Mecânica Computacional and Visualização (LMCV). FASTModDef focus in the modification of existing analysis data, or preliminar analysis model(FEM mesh). It focus in definition and modification of analysis attributes, and also providesbasic refinement routines. It support both 2D models (e.g. plante stress, plate, plane frameand truss), and 3D models (solid, surface shells and 3D frames and space truss) aresupported. FAST ModDef is written in C++ using Qt 6 framework for user interfaceinteraction and OpenGL 4 for rendering. The program data structure (i.e. topology,geometry and simulation data) is detailed, as well the routines used for rendering andmanipulation of the analysis model. Moreover, the impact of the software in manyacademic activities (graduation and post-gradutaion courses) at LMCV is discussed.