Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
EXPERIMENTAL PROCEDURE FOR ESTIMATION OF POISSON FUNCTION OF HIPERELASTIC ANISOTROPIC MATERIAL
Submission Author:
Carolina Seixas Moreira , RJ
Co-Authors:
João Carlos Andrade de Deus Filho, Carolina Seixas Moreira, Luiz Nunes
Presenter: João Carlos Andrade de Deus Filho
doi://10.26678/ABCM.COBEM2021.COB2021-0234
Abstract
The Poisson function is important because it describes the contraction/expansion behavior of a material in a direction perpendicular to the applied stress in finite strains. Due to disagreements in literature related to auxetic behavior in biological tissues and because of the complexity associated with the estimation of Poisson’s function, there is the necessity of more reliable experimental data in this field. Testing of biomaterials pose the ultimate challenge in mechanical testing due to the complexity associated with fixing soft tissues and achieving the boundary condition reliably. Besides, estimate Poisson’s function is a non-trivial task. Accordingly, the purpose of this paper is to propose an experimental procedure to estimate Poisson’s function of a fibrous soft tissue. This procedure was performed on a composite of silicone rubber reinforced with cotton fabric because fibrous soft tissues are commonly studied in the context of hyperelastic anisotropic materials. Tensile tests were performed following three different test procedures. Two- and three-dimensional Digital image correlation method were used to access the displacement full-fields during the tests. The results showed that Poisson function values were bigger than the classic value of Poisson ratio for rubbers, what could be influenced by the cotton fabric. The inclusion of a PTFE support did not produce a substantial improvement. For specimens with strongest fibers positioned at 0°), the use of DIC 3D method presents the lowest standard deviations despite higher reprojection errors, while for the ones with strongest fibers angled 90°, the others procedures seem to produce more repeatable results.
Keywords
Poisson’s function, hyperelastic materials, Composite Materials, Digital Image Correlation
