Static and Dynamic Mechanical Properties of 3D printed Digital Materials

In this work, using a commercially available polyjet printer (Stratasys J850 Prime 3D printer), digital materials with varying concentrations of viscoelastic Agilus30 and Vero plastic materials are created and studied under static and dynamic loading. Digital and hybrid materials with varied Shore A hardness values of 30, 60, and 95 are produced by mixing Agilus30 Black with VeroMagentaV. Then their mechanical damage behavior was studied. For static tensile tests, dog-bone specimens are used at different strain rates. Rectangular samples are used when an elliptical-shaped defect is introduced in the center. To capture the energy absorption characteristics of the printed samples, dynamic impact experiments are conducted using a drop mass impact machine. It is observed that the hybrid material SH95 mostly deforms more rigidly, while the hybrid material SH30 and SH60 exhibit more elongation and flexibility. In other words, we observe that increasing SH level stiffens the hybrid materials. The total impulse or momentum change of the impact event is a clear indicator of the performance of a dynamically loaded material. In terms of energy absorption, the longer time a load can be dissipated over indicates a “more protective” material. We observed that the time in which the compression phase of the impact event happened over got larger with the increasing concentration of Agilus30. As such, the drop impact experiment reveals a nonlinear link between material composition and acceleration reduction. Overall, we observe that the static and dynamic mechanical properties of the hybrid materials can be tuned by varying the processing conditions and compositions.