Avaliação Numérica de propriedades elásticas de estruturas celulares

Abstract

Since the beginning of industrial processes and techniques of mass production, it has been desired to give the best properties to the materials and components made. Frequently, these properties were obtained by selection, mixture or transformation of materials. Could be selected, for example, a heat-treated steel alloy, in order to meet the necessary requirements. The structural design was considered only in a macro view, focused on meeting the geometric shape of the product and its proper function. With a growing demand for lighter and more resistant structures, the industry began to consider the effects of arrangement in a micro view of the structural design of parts and materials. Thus, a tendency emerged for the use of cellular structures. This type of structure is characterized by the repetition of geometric shapes around empty cores. That is, the edges of this chosen geometric shape are the elements that actually make up the material. This makes it possible not only to save material, but to reduce the total mass of the final product, making it lighter. Such structures have several advantages when it comes to elastic properties and are being used and applied in various industry sectors, such as automotive, aeronautics and aerospace. However, knowledge of the properties of these types of structures is still superficial and not properly documented. Therefore, the study and possible applications of various types and setups of cellular structures are shown as a subject of great interest in the current industrial and economic scenario. Because of this, using computational techniques, such as the finite element method in conjunction with the Abaqus tool and the design of experiments technique (DOE), the proposition of the present study is to perform a comparative evaluation of the Young modulus and Poisson coefficient of the hexagonal cellular structure (also known as honeycomb), as a function of the variation of geometric parameters of cell angle, cell size and volumetric density. The scope of the study includes the evaluation, through results of various simulations, of influence, if there is any, of these variations on the mentioned properties. With that, it is desired to establish a theoretical base, sufficient to aid on the choice of a proper geometry of this type of cellular structure (honeycomb) for possible applications and project requirements. The present study has confirmed the great influence of the cell angle in the Poisson coefficient and of the volumetric density in the Young modulus. It was not possible, though, to obtain more accurate equations for estimating this properties.