Influence of the Geometric and Mechanical Characteristics on the Response of Homogeneous Isotropic Materials Under the Brazilian Splitting Test

The present paper concerns the study of the influence of some geometrical parameters, in particular the depth-to-height ratio, and some mechanical properties, in particular Young’s modulus and Poisson’s ratio, on the response of homogeneous isotropic specimens subjected to the Brazilian splitting test. For this purpose, principal stresses and strains are evaluated at the specimen barycenter through finite element analyses carried out in the ANSYS environment. The relevant analyses are performed by adopting systematic variations in both geometrical and mechanical parameters within suitably defined ranges. The obtained numerical results are compared with commonly adopted reference stresses from the literature, showing that the plane stress assumption is independent of material properties for low depth-to-height ratios, and it is generally not realistic under standard testing conditions. Furthermore, the obtained results prove that the tensile principal stress typically assumed in the literature overestimates the actual value. Moreover, the strain field analysis indicates that the validity of the plane strain hypothesis depends jointly on the geometrical and mechanical characteristics of the specimen. Finally, the study proposes a graphical approach for the estimation of the actual tensile principal stress starting from conventional literature-based values, accounting for specimen-specific parameters. Future work will include the numerical validation of the behavior of the principal stresses along the specimen axis, as well as the experimental validation of the numerical results on a specimen basis, for instance, by employing full-field, contactless displacement measurement techniques.