Elaboration Et modélisation d’un matériau cellulaire auxetique.

Abstract

Currently, cell materials are used in various sectors, such as automobile, transport and aerospace. A cell solid is a solid consisting of a connected network of solid links and/and plates forming the edges and the faces of cells. This type of materials have many beneficial properties such as, density, rigidity and resistance specific to flexion, and an ability to support large static and cyclical flowering loads for long periods. These structural properties are used not only in sandwich panels but also more general in applications where weight constitutes in terms of optimization the objective function for the proper design of mechanical subjects. As an indication, we can cite the automotive, aeronautical and naval design and manufacturing field. A good design of a mechanical object depends on two criteria: increased mechanical performance (robustness) and minimization of mass (economic lightness). The main objective of this study is to propose a methodology which makes it possible to provide preliminary choices of structures which display mechanical performance well suited to needs. Thus, on demand, the manufacture of new cellular structures is offered with adaptable mechanical properties according to the technology and industrial application field. When we have combined two types of cells (cells in honeycomb and retention cells) into a single structure and modified cell relationships, we have obtained three types of structures (traditional bee nest, relationship to emotions and fish ratio Null (ZPR)) and we have also found that it is possible to maintain a constant Young module with the variation of the fish coefficient, and this is what gives us the possibility of controlling its mechanical properties without modifying the properties cell geometrics, only modifying the proportions of cells. The digital models have been generated and compared to the results obtained from structures manufactured experimentally by the 3D printer, where the Young module, the fish factor and the compression deformation are used as a comparison criterion and shows a good concordance between the results of the three investigative approaches respectively analytical, digital, and experimental simulations.