Estimating equibiaxial stress-strain relation based on non-homogeneous biaxial measurement

This study investigates the influence of geometry on stress distributions in equibiaxial testing of rubber-like materials using hyperelastic models.Two geometries were examined, characterized by parameters specifying configurations like corner angles and normalized radii.A finite element approach was employed to simulate deformation under equibiaxial stretching, revealing non-homogeneous stress states.Apparent stress ratios were derived to evaluate geometry-induced deviations from purely equibiaxial stress-strain behavior.Results highlight the significance of geometrical factors in stress distributions.The findings offer insights for optimizing specimen designs for equibiaxial material characterization and improving the accuracy of extracted material properties.