Design of a Compact Versatile Testing Rig for Elastomers

The mechanical characterization of elastomers requires particular attention to multiaxial deformation states, as their service behavior is rarely governed by simple loads. Instead, performance and failure mechanisms are strongly influenced by complex, combined stress states. The present work introduces a compact electromechanical tension–torsion testing machine capable of applying axial and torsional loads both independently and synchronized for multiaxial testing. The system also enables torsional cyclic tests over a wide range of frequencies with efficient stress reversal through a “zero-backlash” actuation solution, while allowing free axial expansion and contraction of the specimen to achieve pure torsion across the full deformation range. The device integrates industrial-grade components within a modular architecture, ensuring reliability, maintainability, and scalability. FE analyses were carried out to optimize the frame design and verify its stiffness under critical load cases. The resulting system provides a versatile and cost-effective solution for complete multiaxial testing and mechanical characterization of elastomers, as well as other materials, expanding current experimental capabilities for academic and industrial research needs.