Testing elastomeric materials that undergo large strains pose challenges especially when establishing failure criteria. The failure criterion for composites and polymers based on finite elasticity published byFeng (1) requires testing under uni-axial and bi-axial stretching modes. The classic inflation of a circular disk for bi-axial stretch mode poses stability and safety challenges. The test can also be sensitive to end constraints resulting in failure of materials at the constraints. Bi-axial stretching with a hemispherical punch is explored in this work. The bi-axial stretching allows controlled and repeatabletesting. It establishes clear and reliable failure mechanism of the material at the poles. Through a combination of testing and numerical methods, the stretch ratios and its relation to failure has been established. The method greatly simplifies testing and provides reliable data for a failure criterion for elastomers in numerical modeling. (1)– A failure criterion for polymers and so biological materials, William W. Feng, John O Hallquist, 5th European LS-DYNA Users Conference.