Both the resolution of structural non-conformities and the development of safe and modern engineering projects presuppose the union of technical knowledge from various disciplines with available technology. The use of the Finite Element Method ( FEM ) presents itself as an option for engineers to be able to present assertive solutions to impasses that, without the use of the method, would be excessively expensive, complex or of dubious reliability.

In other words, the use of FEM as a basis for performance computer simulations is a very interesting resource for guaranteeing the quality and reliability of engineering projects.

To review the basic concepts of FEM, check out the article: Understanding the Finite Element Method. To delve deeper into the subject and understand its relevance in modern engineering, continue reading this article.

What is the WEF?

The Finite Element Method advocates dividing the domain of a problem into smaller parts that interact with each other, allowing the problem to be solved using differential equations.

This process, also known as discretization, facilitates the analysis of engineering problems, since it simplifies the complex geometry of various objects and equipment by dividing them into small parts, as illustrated in Figure 1.

Figure 1: Detailed view of an FEM model mesh - SOURCE: Kot Collection.

This approach allows each of the small elements, limited by contours and with known behavior, to represent the continuous domain for the material being simulated.

It is worth pointing out that, depending on the purpose of the analysis, the elements can have different shapes, such as: triangle, square, tetrahedron, pentagon, hexahedron or other less common shapes.

Figure 2: Practical application of mesh construction with details for the elements - SOURCE: Kot Collection.

When applying the FEM

After understanding the most fundamental concept, it is necessary to ask how these elements relate to each other. Each of these small elements is connected by points, called "nodes". The set formed between the nodes and the elements is called a "mesh". The accuracy of the analysis using FEM will depend on the number of subdivisions adopted, since this choice will determine the size, number and shape of the finite elements.

This simplification makes it possible to apply computational analysis to each of these small elements. In this way, it is possible to efficiently analyze the overall performance of a structure and components whose behavior is initially complex to understand. We have, for example, various applications in industry, such as the metal structures of warehouses, industrial buildings, overhead cranes, metal structures, port equipment, belt conveyors, among others.

When solving problems using this technique, it should be considered that, in general: the smaller the elements, i.e. the greater the number of them in a given mesh chosen for FEM analysis, the more accurate the results will be. However, it should be borne in mind that the number of elements directly influences the computational processing time. Depending on the characteristics of the structure to be analyzed and the load distribution, there is a certain limit for reducing the number of elements. Beyond this limit, the gain in accuracy is negligible and disproportionate to the associated computational cost.

Thus, knowing the fundamentals of the technique allows for better use of software that performs análise por elementos finitos, as well as enabling a more assertive, consistent and reliable interpretation of the results presented by them.

Before starting a study, some important requirements must be defined in order to allow proper computer modeling. It is necessary to have detailed drawings of the structure to be analyzed, containing information on component geometries and connections, as well as material properties. If this information is not available, a field survey and material property tests should be carried out.

Kot Engenharia has the experience and resources needed to carry out simulations and applications of the finite element method. Contact our team for more information!

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FAQ

1. O que é e como funciona o Método dos Elementos Finitos (MEF/FEM)?

É uma técnica que divide o domínio de uma geometria complexa em partes menores por meio da discretização. Cada pequena parte é analisada numericamente por equações diferenciais, permitindo avaliar com precisão a performance geral da estrutura.

2. O que são elementos, nós e malha no MEF?

• Elementos: As pequenas peças geométricas subdivididas (como triângulos, tetraedros ou hexaedros).

• Nós: Os pontos geométricos que conectam os elementos entre si.

• Malha: O conjunto completo formado pela união de todos os nós e elementos do modelo.

 

3. Como a quantidade de elementos afeta a precisão da simulação?

Em geral, quanto menores e mais numerosos forem os elementos da malha, maior será a precisão dos resultados. No entanto, o aumento da quantidade de elementos exige mais tempo de processamento computacional.

 

4. Existe um limite para o refinamento da malha?

Sim. A partir de um determinado nível de refinamento, o ganho de precisão torna-se desprezível, não justificando o alto custo e o tempo extra de processamento computacional exigidos.

 

5. Em quais estruturas industriais o MEF é mais aplicado?

O método é amplamente utilizado na análise de estruturas metálicas de galpões, prédios industriais, pontes rolantes, equipamentos portuários e transportadores de correia.

 

6. Quais dados são necessários antes de iniciar uma análise por MEF?

É essencial ter os desenhos técnicos detalhados da estrutura (com geometrias de componentes e conexões) e as propriedades dos materiais. Caso essas informações não existam, é necessário realizar um levantamento de campo e ensaios de materiais.