DYNAMIC RESPONSES OF 3-D PRINTED POLYMERIC MATERIALS UNDER A WIDE RANGE OF STRAIN RATES

The mechanical behavior of 3D printed polymeric materials is critical for applications in additive manufacturing, soft robotics, biomedical devices, and mechanical metamaterial designs. This study investigates the strain rate-dependent mechanical behaviors 3D printed polymers fabricated using a multi-material 3D printer (Stratasys Connex 3) through systematic mechanical experiments under a large range of strain rate from 10^-2 to 10³ s^-1. Quasi-static indentation tests were conducted to evaluate deformation and failure under localized static loading, while dynamic puncture and compression tests were conducted via a drop tower (Zwick Amsler HIT600F) to characterize energy absorption and bulk properties under impact. To characterize rate-dependent constitutive relation, both quasi-static compression and Split Hopkinson Pressure Bar (SHPB) tests were conducted. The results show increased stiffness and yielding stress for higher strain rates, alongside a transition from ductile to brittle-like failure modes. These findings enhance the understanding of mechanical behaviors of 3D printed polymers under dynamic loading, offering critical data for material modeling and structural design in high-performance applications. The work informs the development of reliable computational models and optimizes additive manufacturing for impact-resistant designs.