Análise de estruturas celulares regulares submetidas a cargas de impacto

Abstract

Honeycomb-like structures are extensively studied as impact absorbers and many studies can be found in the literature. Despite this, due to the great variety of applicability of the structures and also its different possibilities of geometries and materials, the research field is still very active. The low density added to the high rigidity of these structures allows the honeycomb panels to absorb a considerable amount of energy through plastic deformation. This makes honeycomb cores extremely attractive for engineering solutions for a wide range of industrial applications, despite being relatively expensive compared to simpler geometry absorbers such as tubes or housings. Therefore, it is important to understand the behavior of the structure in a very clear and detailed way. In this context, the present work is inserted, whose objective is to study, using finite element modeling through commercial software, the behavior of honeycombs subjected to impact loads in their extension plane. First, the influence of the shape of the cells of the nuclei is investigated to, in sequence, study the influence of the size of the cells. Finally, a study of the cores under different impact velocities is carried out and the failure mechanism of the structures analyzed. A different behavior of the cores is observed at different impact speeds, both in terms of impact force reduction and kinetic energy absorption. There is a significant increase in the energy absorption efficiency of the cores with increasing speed and two different behaviors are identified in relation to the force transmitted to the base of the structure. Increasing the cell size proves to be an interesting tool to reduce the impact force and increase the useful length of the simulated structures. Through a normalization of the comparison parameters in the structures, it is inferred that the hexagonal structure with an opening angle of 15 degrees showed the best behavior for the simulated velocities.