Contribution of Finite Elements Analysis to engineering design

Design is a complex creative process. It consists of developing a product or system in accordance with a customer's requirements, and in compliance with certain rules or standards, or the availability of certain materials, components or means of production, which amounts to limiting the product's creative scope. It must also guarantee the company's financial profitability.

Drawing up a functional specification (CdCF, see [A 5 090] ) enables us to understand the complexity of the project by structuring it into functions and constraints, to which are associated assessment criteria, specifying their level and flexibility. Some of these functions and constraints are of particular interest to us here. These are those that refer to the product's mechanical, thermal, electrical or electromagnetic behavior. But whether or not they have been formulated in a CdCF, these behavioral functions and constraints are present in every project, and tools and methods are needed to design a product capable of satisfying them.

When it comes to the mechanical behavior of a product, the engineer or designer has a wide range of methods at his or her disposal, including :

• methods based on "professional" knowledge such as abacuses, empirical laws, databases, etc. ;

• simplified calculation methods such as strength of materials ;

• more elaborate calculation methods, generally supported by computer tools, with the finite element method (FEM) being the most widely used;

• optimization methods.

The relevant implementation and use of these methods, and in particular the finite element method, are discussed in this article. The stakes are high, since in a highly competitive industrial context, the aim is to :

• reduce costs (optimize shapes and material volumes, choose materials, reduce the number of prototypes, etc.);

• reduce lead times (limit the number of iterations in the design process, propose viable solutions directly from a behavioral point of view, better target testing, etc.);

• improve quality (ensure compliance with various functions and constraints in terms of reliability, comfort, ergonomics, etc.).

The field of application of finite element methods is vast. They have proven...