Integrating open source codes for solid modeling and automatic mesh generation in FEM applications

The applications of the Finite Element Method (FEM) for three-dimensional domains are already well documented in the framework of Computational Electromagnetics. However, despite the power and reliability of this technique for solving partial differential equations, there are only a few examples of open source codes available and dedicated to the solid modeling and automatic constrained tetrahedralization, which are the most time consuming steps in a typical three-dimensional FEM simulation. Besides, these open source codes are usually developed separately by distinct software teams, and even under conflicting specifications. In this paper, we describe an experiment of open source code integration for solid modeling and automatic mesh generation. The integration strategy and techniques are discussed, and examples and performance results are given, specially for complicated and irregular volumes which are not simply connected. © 2011 IEEE.

Desenvolvimento de uma plataforma de software para a modelagem digital de terrenos baseada em TIN

Topographical surfaces can be represented with a good degree of accuracy by means of maps. However these are not always the best tools for the understanding of more complex reliefs. In this sense, the greatest contribution of this work is to specify and to implement the architecture of an opensource software system capable of representing TIN (Triangular Irregular Network) based digital terrain models. The system implementation follows the object oriented programming and generic paradigms enabling the integration of various opensource tools such as GDAL, OGR, OpenGL, OpenSceneGraph and Qt. Furthermore, the representation core of the system has the ability to work with multiple topological data structures from which can be extracted, in constant time, all the connectivity relations between the entities vertices, edges and faces existing in a planar triangulation what helps enormously the implementation for real time applications. This is an important capability, for example, in the use of laser survey data (Lidar, ALS, TLS), allowing for the generation of triangular mesh models in the order of millions of points.

Desenvolvimento de software utilizando a técnica sph (smoothed particle hydrodynamics) na geração de ondas de submersão

Pós-graduação em Engenharia Elétrica - FEIS

Avaliação das condições de contorno da teoria de Hertz, comparando os resultados analíticos e numéricos a partir de simulações em software de elementos finitos

The objective of this study was to present the comparison between analytical and numerical results trying to identify the differences and behaviors of the variation of the principal stresses and the maximum contact pressure for different model configurations. The analytical equations of the theory of Hertz from the boundary conditions adopted by him were differences are shown. A step-by-step of developing the model indicating the geometric dimensions, surface contact, type of contact, the formulation used by the software, type of mesh, as well as the boundary conditions and load was presented. In the results, the stresses calculated analytically and compared with the stresses obtained by the finite element simulation software indicating the changes have been made

Projeto mecânico de um modelo para túnel de vento e validação de seus componentes à partir de simulações em software de elementos finitos

The objective of this study was to develop a model that allows testing in the wind tunnel at high angles of attack and validates its most critical components by analyzing the results of simulations in finite element software. During the project this structure suffered major loads identified during the flight conditions and, from these, we calculated the stresses in critical regions defined as the parts of the model that have higher failure probabilities. All aspects associated with Load methods, mesh refining and stress analysis were taken into account in this approach. The selection of the analysis software was based on project needs, seeking greater ease of modeling and simulation. We opted for the software ANSYS® since the entire project is being developed in CAD platforms enabling a friendly integration between software's modeling and analysis