AUXETIC MATERIAL DESIGN THROUGH STRUCTURAL OPTIMIZATION APPROACH

Resumo

Unlike conventional materials, an auxetic material has negative Poisson’s ratio, that is, it
increases the size of its cross-section when is under traction and decrease when is compressed. The
auxetic structural behavior can provide many benefits, since the structural material may acquire
notable mechanical properties, such as increased resistance to impact. Due to this improved impact
absorption capacity, the auxetic materials have great potential for use in the aerospace structures. In
this work, parametric optimization has been applied to develop a re-entrant structure (periodic cell)
that simulates the behavior of the auxetic material microstructure. Thus, the auxetic behavior arises
from the mechanism deformation of geometric configuration of the re-entrant structure. The main
motivation of this work is to contributes with a more systematic methodology to design of the auxetic
structures, make it independent of the designer expertise. Some 3D re-entrant auxetic structures of the
literature are adopted as initial design domain and a parametric optimization is carried out to obtain
optimized dimensional configurations for the geometry of the auxetic structure. Dimensional
parameters of the domain, such as angles, wall thickness, height, and width, are considered as design
variables in the optimization problem, in which the objective function is formulated to maximize de
behavior of the auxetic structure (negative Poisson’s ratio). Computational simulations of finite
element models are carried out to evaluate the optimized auxetic structures.